Radiators for terahertz electromagnetic radiation and integrated circuits comprising the same

Abstract

A radiator for terahertz electromagnetic radiation. The radiator comprises one or more radiator units. Each of the one or more radiator units comprises an oscillator device operable to generate third harmonic power, and a patch antenna device operably coupled with the oscillator device to radiate terahertz electromagnetic radiation from the generated third harmonic power. Some embodiments of the invention provide a two-dimensional scalable coupling topology suitable for large array formation to achieve a desired coherent oscillation mode, with integrable differential patch antennas radiating third harmonics without the need for a lens to achieve high output frequencies in excess of 600 GHz.

Description

Technical Field

[0001] This invention relates to a radiator for terahertz (THz) electromagnetic radiation. Background Technology

[0002] Electromagnetic radiation in the terahertz band can be used in a variety of applications such as imaging, spectroscopy, and communications.

[0003] Some existing devices that generate electromagnetic radiation in the terahertz band are silicon-based devices (such as silicon arrays). The problem is that, since the terahertz band is typically beyond the maximum oscillation frequency of silicon, these existing devices may suffer from low output power and / or low efficiency. Summary of the Invention

[0004] In a first aspect of the invention, a radiator for terahertz electromagnetic radiation is provided. The radiator includes one or more radiator units. Each of the one or more radiator units includes: an oscillator device operable to generate third harmonic power, and a patch antenna device operable to be coupled to the oscillator device to radiate terahertz electromagnetic radiation according to the generated third harmonic power.

[0005] The terahertz electromagnetic radiation provided by the aforementioned radiator can range from about 0.1 terahertz to about 10 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.2 terahertz to about 5 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.3 terahertz to about 3 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.3 terahertz to about 1 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.4 terahertz to about 0.8 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.4 terahertz to about 0.7 terahertz. In some embodiments, the terahertz electromagnetic radiation ranges from about 0.6 terahertz to about 0.7 terahertz. In some embodiments, the terahertz electromagnetic radiation is from about 0.64 terahertz to about 0.69 terahertz.

[0006] In some embodiments, the oscillator device includes: a first oscillator operable to generate third harmonic power, a second oscillator operable to generate third harmonic power, and a coupler electrically coupling the first oscillator and the second oscillator.

[0007] In some embodiments, the coupler includes an even-mode suppression coupler for enabling or maintaining an anti-phase coupling mode between the first oscillator and the second oscillator.

[0008] In some embodiments, the even-mode suppression coupler includes: a transmission line device electrically connected between a first oscillator and a second oscillator, and a capacitor device electrically connected to the transmission line device and usable to facilitate a short circuit of the even-mode impedance. In some examples, the transmission line device may include a transmission line or consist only of a transmission line. In some examples, the transmission line may be straight. In some examples, the capacitor device may include or consist only of a capacitor. In some examples, the transmission line has a length, and the capacitor is electrically connected in the middle or near the length of the transmission line.

[0009] In some embodiments, the first oscillator and the second oscillator are arranged to differentially feed the patch antenna device.

[0010] In some embodiments, the patch antenna device includes: a first patch element operatively coupled to a first oscillator and a second oscillator, and a second patch element operatively coupled to the first oscillator and the second oscillator. In some embodiments, the first patch element and the second patch element are substantially the same in shape, size, and material.

[0011] In some embodiments, each of the first oscillator and the second oscillator includes a transistor arrangement. In other words, the first oscillator has one transistor arrangement, and the second oscillator has one (i.e., another) transistor arrangement. In some embodiments, the transistor arrangement includes a first transistor having a gate, a source, and a drain, and a second transistor having a gate, a source, and a drain. The first transistor and the second transistor are operatively coupled to operate in phase.

[0012] The first transistor and the second transistor can be solid-state electronic devices, such as silicon-based solid-state electronic devices. For example, the first transistor and the second transistor can be field-effect transistors (FETs). The first transistor and the second transistor can be arranged (e.g., controlled) to selectively operate in the active region, the cutoff region, and the transistor region, respectively, to facilitate the generation of third harmonic power.

[0013] In some embodiments, the gate of the first transistor and the gate of the second transistor are electrically connected to each other.

[0014] In some embodiments, the source of the first transistor and the source of the second transistor are electrically connected to each other.

[0015] In some embodiments, the gate terminals of the first transistor and the second transistor are electrically connected to an even-mode short-circuit coupler.

[0016] In some embodiments, each of the first oscillator and the second oscillator further includes: a first circuit arrangement electrically connected to the source of the first transistor, a second circuit arrangement electrically connected to the source of the second transistor, a third circuit arrangement electrically connected to the drain of the first transistor and operatively coupled to a patch antenna arrangement (e.g., to a first patch element), and a fourth circuit arrangement electrically connected to the drain of the second transistor and operatively coupled to a patch antenna arrangement (e.g., to a second patch element). In other words, the first oscillator has its own first to fourth circuit arrangements, and the second oscillator has its own first to fourth circuit arrangements.

[0017] In some embodiments, the first circuit arrangement includes a capacitor for promoting oscillation and a transmission line arrangement for supplying power. The capacitor and transmission line arrangements of the first circuit arrangement are electrically connected in parallel. In some examples, the capacitor of the first circuit arrangement is grounded. In some examples, the capacitor of the first circuit arrangement includes or includes only one capacitor. In some examples, the transmission line arrangement of the first circuit arrangement is grounded. In some examples, the transmission line arrangement of the first circuit arrangement includes or includes only one curved transmission line. In some examples, the curved transmission line is a wavy transmission line with multiple bends.

[0018] In some embodiments, the second circuit arrangement includes a capacitor for promoting oscillation and a transmission line arrangement for supplying power. The capacitor and transmission line arrangements of the second circuit arrangement are electrically connected in parallel. In some examples, the capacitor of the second circuit arrangement is grounded. In some examples, the capacitor of the second circuit arrangement includes or includes only one capacitor. In some examples, the transmission line arrangement of the second circuit arrangement is grounded. In some examples, the transmission line arrangement of the second circuit arrangement includes or includes only one curved transmission line. In some examples, the curved transmission line is a wavy transmission line with multiple bends.

[0019] In some embodiments, the third circuit device includes: a transmission line device operatively coupled to the patch antenna device and an AC short-circuit termination device electrically connected to the transmission line device. In some examples, the AC short-circuit termination device of the third circuit device includes a grounding capacitor device electrically connected to the transmission line device. In some examples, the grounding capacitor device includes or includes only a grounding capacitor. In some examples, the transmission line device of the third circuit device includes or includes only: a first transmission line portion, one end of which is electrically connected to the AC short-circuit termination device, and a second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device for capacitively feeding the patch antenna device. A DC power supply voltage may be applied between the first transmission line portion and the AC short-circuit termination device. In some examples, the first transmission line portion is straight. In some examples, the second transmission line portion is straight. In some examples, the first and second transmission line portions are substantially perpendicular.

[0020] In some embodiments, the fourth circuit device includes: a transmission line device operatively coupled to the patch antenna device, and an AC short-circuit termination device electrically connected to the transmission line device. In some examples, the AC short-circuit termination device of the fourth circuit device includes a grounding capacitor device electrically connected to the transmission line device. In some examples, the grounding capacitor device includes or includes only a grounding capacitor. In some examples, the transmission line device of the fourth circuit device includes or includes only: a first transmission line portion, one end of which is electrically connected to the AC short-circuit termination device, and a second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device for capacitively feeding the patch antenna device. A DC power supply voltage may be applied between the first transmission line portion and the AC short-circuit termination device. In some examples, the first transmission line portion is straight. In some examples, the second transmission line portion is straight. In some examples, the first and second transmission line portions are substantially perpendicular.

[0021] In some embodiments, the transmission line arrangements of the first circuit arrangement and the second circuit arrangement are arranged substantially symmetrically about a reflection symmetry axis. The reflection symmetry axis may be parallel to or collinear with the major axis of the even-mode suppression coupler transmission line.

[0022] In some embodiments, the transmission line arrangements of the third circuit device and the fourth circuit device are arranged generally symmetrically about a reflection symmetry axis. The reflection symmetry axis may be parallel to or collinear with the major axis of the even-mode converter transmission line.

[0023] In some embodiments, the patch antenna device includes an on-chip patch antenna array.

[0024] In some embodiments, the first patch element is electrically coupled (e.g., capacitively coupled) to the third circuitry of the first oscillator and the third circuitry of the second oscillator.

[0025] In some embodiments, the second patch element is electrically coupled (e.g., capacitively coupled) to the fourth circuitry of the first oscillator and the fourth circuitry of the second oscillator.

[0026] In some embodiments, the first transistor of the first oscillator and the first transistor of the second oscillator are arranged to selectively or alternately provide third harmonic power to the first patch element. For example, in one cycle, the first transistor of the first oscillator may provide third harmonic power to the first patch element for approximately half a cycle (cumulatively or continuously), while the first transistor of the second oscillator may provide third harmonic power to the first patch element for approximately the other half cycle (cumulatively or continuously).

[0027] In some embodiments, the second transistors of the first oscillator and the second transistor of the second oscillator are arranged to selectively or alternately provide third harmonic power to the second patch element. For example, in one cycle, the second transistor of the first oscillator may provide third harmonic power to the second patch element for approximately half a cycle (cumulatively or continuously), while the second transistor of the second oscillator may provide third harmonic power to the second patch element for approximately the other half cycle (cumulatively or continuously).

[0028] In some embodiments, the first patch element is part of a larger patch (e.g., half).

[0029] In some embodiments, the second patch element is part of a larger patch (e.g., half of it).

[0030] In some embodiments, in a plan view, the transmission line of the dipole-mode suppression coupler is arranged between the first patch element and the second patch element.

[0031] In some embodiments, in a plan view, the first patch element and the second patch element are arranged approximately symmetrically about a reflection symmetry axis. The reflection symmetry axis may be parallel to or intersect with the major axis of the even-mode suppression coupler transmission line.

[0032] In some embodiments, in a plan view, the first oscillator and the second oscillator are arranged approximately symmetrically about a reflection symmetry axis. The reflection symmetry axis may be an axis that divides the first patch element and the second patch element into two parts.

[0033] In some embodiments, one or more radiator units include a plurality of radiator units operatively coupled to each other.

[0034] In some embodiments, a plurality of radiator units are arranged in an array having one or more rows.

[0035] In some embodiments, a plurality of radiator units are arranged in an array having multiple rows, each row including at least one radiator unit, and all the first and second oscillators of the plurality of radiator units form a multi-row oscillator and a multi-column oscillator. In some embodiments, the number of rows and columns of the oscillator are the same. In some embodiments, the number of rows and columns of the oscillator are different.

[0036] In some embodiments, the plurality of radiator units include at least a first radiator unit and a second radiator unit arranged in the same row, and the radiator includes a coupling means for electrically coupling the first radiator unit and the second radiator unit in the same row.

[0037] In some embodiments, the coupling device (electrically coupling the first radiator unit and the second radiator unit in the same row) includes a dipole-mode suppression coupler for enabling or maintaining an anti-phase coupling mode between (i) a first oscillator of one of the first radiator units and the second radiator unit; and (i) a second oscillator of the other of the first radiator unit and the second radiator unit.

[0038] In some embodiments, the even-mode short-circuit coupler of the coupling device includes: a transmission line device electrically connected between (i) a first oscillator and a second radiator unit of one of the first radiator units, and (ii) between a second oscillator and a second radiator unit of one of the first radiator units; and a capacitor device electrically connected to the transmission line device and used to facilitate an even-mode impedance short circuit. In some examples, the transmission line device may include a transmission line or consist only of a transmission line. In some examples, the transmission line may be straight. In some examples, the capacitor device may include or consist only of a capacitor. In some examples, the transmission line has a length, and the capacitor is electrically connected in the middle or near the length of the transmission line. In some examples, the even-mode suppression coupler is electrically connected between (i) the gates of the first and second transistors of the second oscillator of the first radiator unit and the gates of the first and second transistors of the first oscillator of the second radiator unit, or (ii) between the gates of the first and second transistors of the first oscillator of the first radiator unit and the gates of the first and second transistors of the second oscillator of the second radiator unit.

[0039] In some embodiments, the plurality of radiator units include at least a first radiator unit and a second radiator unit arranged adjacent to each other, and the radiator includes a coupling device for electrically coupling the first radiator unit and the second radiator unit arranged adjacent to each other.

[0040] In some embodiments, the coupling device (electrically coupling the first radiator unit and the second radiator unit in adjacent rows) includes: a first coupler electrically connected between the first oscillator of the first radiator unit and the first oscillator of the second radiator unit, and a second coupler electrically connected between the second oscillator of the first radiator unit and the second oscillator of the second radiator unit.

[0041] In some embodiments, the first coupler includes a first odd-mode short-circuit coupler for enabling or maintaining an in-phase coupling mode between a first oscillator of a first radiator unit and a first oscillator of a second radiator unit. The second coupler includes a second odd-mode short-circuit coupler for enabling or maintaining an in-phase coupling mode between a second oscillator of a first radiator unit and a second oscillator of a second radiator unit.

[0042] In some embodiments, the first odd-mode short-circuit coupler includes: a transmission line arrangement electrically connected between a first oscillator of the first radiator unit and a first oscillator of the second radiator unit; a first capacitor arrangement electrically connected between the transmission line arrangement and the first oscillator of the first radiator unit and usable for facilitating an odd-mode impedance short circuit; and a second capacitor arrangement electrically connected between the transmission line arrangement and the first oscillator of the second radiator unit and usable for facilitating an odd-mode impedance short circuit. In some examples, the transmission line arrangement includes or only includes transmission lines. In some examples, the transmission lines are straight. In some examples, the first capacitor arrangement includes or only includes a capacitor. In some examples, the second capacitor arrangement includes or only includes a capacitor. In some embodiments, the first odd-mode short-circuit coupler is electrically connected between the source of a second transistor of the first oscillator of the first radiator unit and the source of a first transistor of the first oscillator of the second radiator unit.

[0043] In some embodiments, the second odd-mode short-circuit coupler includes: a transmission line arrangement electrically connected between a second oscillator of the first radiator unit and a second oscillator of the second radiator unit; a first capacitor arrangement electrically connected between the transmission line arrangement and the second oscillator of the first radiator unit and usable for facilitating an odd-mode impedance short circuit; and a second capacitor arrangement electrically connected between the transmission line arrangement and the second oscillator of the second radiator unit and usable for facilitating an odd-mode impedance short circuit. In some examples, the transmission line arrangement includes or only includes transmission lines. In some examples, the transmission lines are straight. In some examples, the first capacitor arrangement includes or only includes a capacitor. In some examples, the second capacitor arrangement includes or only includes a capacitor. In some embodiments, the second odd-mode short-circuit coupler is electrically connected between the source of the second transistor of the second oscillator of the first radiator unit and the source of the first transistor of the second oscillator of the second radiator unit.

[0044] In some embodiments, a plurality of radiator elements are arranged in an array, each array having multiple rows, each row including at least one radiator element. In some embodiments, the array includes or includes only a plurality of subarrays, each subarray comprising some of the rows. In some embodiments, each of the plurality of subarrays is arranged to withstand a respective bias voltage. The bias voltage may affect one or more characteristics of the terahertz electromagnetic radiation provided by the radiator. One or more characteristics of the terahertz electromagnetic radiation may include one or more of radiation pattern, direction, etc. In some embodiments, the bias voltages applied to at least two of the plurality of subarrays are different. In some embodiments, the bias voltages applied to all of the plurality of subarrays are different.

[0045] In some embodiments, the radiator is manufactured using CMOS technology, such as a 65-nanometer CMOS process / technology.

[0046] In some embodiments, the radiator is arranged in or formed within an integrated circuit (chip). Terahertz electromagnetic radiation may radiate from one side (e.g., the front) of the integrated circuit.

[0047] In some embodiments, the radiator is a terahertz radiator configured solely for terahertz electromagnetic radiation. In some embodiments, the radiator is configured for terahertz electromagnetic radiation as well as electromagnetic radiation at one or more other frequencies or bands. In some embodiments, the radiator is configured to provide terahertz electromagnetic radiation as well as electromagnetic radiation at one or more other frequencies or bands, and the optimal operating mode of the radiator may be to provide terahertz electromagnetic radiation.

[0048] In a second aspect, an integrated circuit is provided, which includes at least one radiator as described in the first aspect.

[0049] In a third aspect, an apparatus comprising at least one radiator as described in the first aspect is provided.

[0050] In some embodiments, the device further includes a thermal management device thermally coupled to the radiator for regulating the temperature of the radiator (e.g., for promoting heat dissipation from the radiator). In some embodiments of the radiator device or formed in an integrated circuit (chip), the thermal management device may be coupled to the back side of the integrated circuit. In some embodiments, the thermal management device includes a passive thermal management device. For example, a passive thermal management device may include a radiator with heat sinks, pins, etc. In some examples, the thermal management device includes an active thermal management device. For example, an active thermal management device may include a fan, a liquid-based heat exchanger, an evaporative heat exchanger, etc.

[0051] In some embodiments, the device lacks any lens relative to the radiator assembly for influencing (e.g., enhancing) the directivity of the terahertz electromagnetic radiation provided by the radiator.

[0052] In a fourth aspect, a system for providing terahertz electromagnetic radiation is provided, the system comprising at least one of the radiators described in the first aspect above. The system may be a sensing system, a communication system, a spectral system, an imaging system, etc. In one example, the system is an active terahertz imaging system for illuminating an object (e.g., a target object). In one example, the system is a cellular (e.g., 5G, 6G, or higher) communication system.

[0053] In a fifth aspect, a system for providing terahertz electromagnetic radiation is provided, the system comprising at least one integrated circuit as described in the second aspect above. The system may be a sensing system, a communication system, a spectral system, an imaging system, etc. In one example, the system is an active terahertz imaging system for illuminating an object (e.g., a target object). In one example, the system is a cellular (e.g., 5G, 6G, 6G+, or similar) communication system.

[0054] In a sixth aspect, a system for providing terahertz electromagnetic radiation is provided, the system comprising at least one device described in the third aspect above. The system may be a sensing system, a communication system, a spectral system, an imaging system, etc. In one example, the system is an active terahertz imaging system for illuminating an object (e.g., a target object). In one example, the system is a cellular (e.g., 5G, 6G, or higher, or similar) communication system. Attached Figure Description

[0055] The performance and advantages of the invention can be further understood by referring to the remainder of this specification and the accompanying drawings, in which the same reference numerals are used for the same component. In some cases, a sub-label is placed after a label followed by a hyphen to indicate one of many similar components. When a label is mentioned without specifically naming an existing sub-label, it refers to all of these similar components.

[0056] Figure 1A This is a schematic circuit diagram illustrating an example of a dual-core (dual-element) oscillator model.

[0057] Figure 1B This is a schematic circuit diagram illustrating examples of even-mode and odd-mode equivalent circuits of a T-type network based on a two-port network.

[0058] Figure 2 This is a schematic diagram of a scalable coupled oscillator array topology for a terahertz electromagnetic radiation radiator in some embodiments of the present invention.

[0059] Figure 3A This is a schematic diagram of a 12×12 coupled oscillator array (as a radiator for terahertz electromagnetic radiation) in one embodiment of the present invention.

[0060] Figure 3B yes Figure 3A A partially enlarged view of the 12×12 coupled oscillator array.

[0061] Figure 4A yes Figure 3A A schematic diagram of a 1×2 element (as a radiating element) in a 12×12 coupled oscillator array.

[0062] Figure 4B yes Figure 3A A schematic diagram of a 1×2 cell in a 12×12 coupled oscillator array, with dimensions labeled;

[0063] Figure 5 This is a schematic circuit diagram, explaining... Figure 4B The equivalent AC lumped circuit at f0 of a quarter circuit in the 1×2 unit.

[0064] Figure 6 This is a schematic circuit diagram illustrating an example simulation setup for studying the nonlinear behavior of transistors (simulation frequency set to 1 GHz).

[0065] Figure 7A It is a graph that displays the simulated drain current waveform (under a given DC bias and basic drive voltage) and the corresponding gate and drain voltage waveforms obtained from the transistor.

[0066] Figure 7B This is a simulated harmonic current diagram of the transistor drain under different fundamental voltages, and a selected fundamental voltage |V. d The three corresponding current waveforms under _f0|.

[0067] Figure 8A It displays the simulated drain current waveform (by changing the second harmonic voltage |V) d _2f0|) and graphs of the corresponding gate and drain voltage waveforms obtained from the transistor.

[0068] Figure 8B It displays the second harmonic drain voltage |V at different transistor drain terminals. d The curve of harmonic current in the drain of a transistor under _2f0|.

[0069] Figure 9A It displays the simulated drain current waveform (by changing the third harmonic voltage |V) d (3f0|) and the corresponding gate and drain voltage waveforms obtained from the transistor.

[0070] Figure 9B It displays the drain voltage at different third harmonics |V of the transistor drain. d A diagram showing the harmonic current in the transistor drain simulation at _3f0|.

[0071] Figure 10 This is a schematic circuit diagram illustrating a simulation setup example for determining the fundamental operating conditions and harmonic load impedance (fundamental frequency set to 225 GHz).

[0072] Figure 11A This is a graph showing the simulated net fundamental output power Po_f0 under different fundamental voltage gain phase differences φ.

[0073] Figure 11B This indicates different fundamental voltages at the drain of the display transistor |V d The graphs of the second and third harmonic currents and the net fundamental output power of the transistor generated by the simulation at time _f0|.

[0074] Figure 12 This indicates the different third harmonic drain-source impedances Z of the transistor at 3f0. dsThe curve of the third harmonic output power Po_3f0 at _3f0.

[0075] Figure 13 This is a schematic circuit diagram, explaining... Figure 4B The AC equivalent circuit of a quarter circuit in the 1×2 unit at 3f0.

[0076] Figure 14A This is the simulated input impedance diagram of the patch antenna at 3f0.

[0077] Figure 14B It is a patch antenna. Figure 4A The cell contains the simulation gain plots at f0 and 3f0.

[0078] Figure 15 It means according to Figure 3A A photomicrograph of an integrated circuit (chip) made of a 12×12 coupled oscillator array.

[0079] Figure 16 It is based on Figure 4A Micrograph of a 1×2 cell (coupled oscillator array) integrated circuit (chip) manufactured using 1×2 cell technology.

[0080] Figure 17 It is a photograph showing an example measuring apparatus for measuring the frequency, radiation pattern, and effective isotropic radiated power (EIRP) of the equipment.

[0081] Figure 18 This is a schematic diagram showing an example of calibration settings for calibrating path loss, mixer conversion loss, and cable loss.

[0082] Figure 19A It is a display Figure 15 A graph showing the measured spectrum of a 12×12 coupled oscillator array.

[0083] Figure 19B Is display and Figure 15 The graph shows the simulation and measurement frequency tuning range related to the 12×12 coupled oscillator array.

[0084] Figure 20 It is a display Figure 15 The simulation and measurement curves of the equivalent isotropic radiated power (EIRP) of the 12×12 coupled oscillator array.

[0085] Figure 21A yes Figure 15 Phase noise measurement of the 12×12 coupled oscillator array at 675 GHz.

[0086] Figure 21B yes Figure 15 12×12 coupled oscillator array and Figure 16 The measured phase noise map of the 1×2 cell (offset 1MHz).

[0087] Figure 22A yes Figure 15 Simulated and measured radiation directions (E-plane and H-plane modes) of a 12×12 coupled oscillator array at 675 GHz.

[0088] Figure 22B yes Figure 15 Simulated directivity and calculated directivity plot of a 12×12 coupled oscillator array.

[0089] Figure 23A yes Figure 15 Simulation and measured radiated power diagram of the 12×12 coupled oscillator array.

[0090] Figure 23B yes Figure 15 Simulation and measurement of DC power consumption of the 12×12 coupled oscillator array.

[0091] Figure 24A yes Figure 15 Simulated phase diagram of a 12×12 coupled oscillator array, where V G1 To V G3 Set to 1V, V G2 Set to 0.8V.

[0092] Figure 24B It's a table that displays the measurements. Figure 15 The bias setting of the radiation pattern of the 12×12 coupled oscillator array.

[0093] Figure 24C It is based on Figure 24B Obtained by the bias settings in Figure 15 The radiation pattern of the beam scan measured by the 12×12 coupled oscillator array.

[0094] Figure 25 This is a schematic diagram of the radiation unit of a terahertz electromagnetic radiation radiator in some embodiments of the present invention.

[0095] Figure 26 This is a schematic diagram of a radiator unit for a radiator used for terahertz electromagnetic radiation in some embodiments of the present invention; and

[0096] Figure 27 This is a schematic diagram of a radiator unit for a radiator used for terahertz electromagnetic radiation in some embodiments of the present invention. Detailed Implementation

[0097] The specification and claims use certain terms to refer to specific components. Those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function. The term "comprising" throughout the specification and claims is an open-ended term and should be interpreted as "comprising but not limited to." "Approximately" means that within an acceptable margin of error, those skilled in the art can solve the technical problem and substantially achieve the technical effect within a certain margin of error.

[0098] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "horizontal", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0099] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0100] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0101] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0102] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0103] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0104] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0105] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in the specification and claims of this patent application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a limitation of quantity, but rather indicate the presence of at least one.

[0106] Degree terms, such as “generally,” “approximately,” “basically,” or similar terms, are used depending on the context to describe actual conditions such as manufacturing tolerances, degradation, trends, tendencies, and imperfections. For example, when a value is modified by a degree term such as “generally,” this expression could include ±10%, ±5%, ±2%, or ±1% of the value.

[0107] Figure 25 A radiator unit 2500 for a radiator used for terahertz electromagnetic radiation is shown in some embodiments of the present invention.

[0108] The radiator unit 2500 generally includes an oscillator device 2502 and a patch antenna device 2504. The oscillator device 2502 can be used to generate third harmonic power (e.g., in the form of current or voltage). The patch antenna device 2504 is operatively coupled to the oscillator device 2502 for radiating terahertz electromagnetic radiation according to the third harmonic power generated by the oscillator device 2502. The oscillator device 2502 may include one or more oscillators, such as one or more transistor-based oscillators. The patch antenna device 2504 may include one or more patch antennas. In some embodiments, the range of terahertz electromagnetic radiation radiated by the patch antenna device 2504 may be: about 0.1 terahertz to about 10 terahertz, about 0.2 terahertz to about 5 terahertz, about 0.3 terahertz to about 3 terahertz, about 0.3 terahertz to about 1 terahertz, about 0.4 terahertz to about 0.8 terahertz, about 0.4 terahertz to about 0.7 terahertz, about 0.6 terahertz to about 0.7 terahertz, or about 0.64 terahertz to about 0.69 terahertz, etc.

[0109] Figure 26 A radiator unit 2600 for terahertz electromagnetic radiation is shown in some embodiments of the present invention. Radiator unit 2600 can be considered as a more specific embodiment of radiator unit 2500.

[0110] The radiator unit 2600 generally includes an oscillator device (having two oscillators 2602A, 2602B and a coupler 2602C) and a patch antenna device 2604. The oscillator device can generate third harmonic power (e.g., in the form of current or voltage). The patch antenna device 2604 is operatively coupled to the oscillator device for radiating terahertz electromagnetic radiation according to the third harmonic power generated by the oscillator device.

[0111] In some embodiments, oscillators 2602A and 2602B are arranged to differentially feed patch antenna device 2604.

[0112] The oscillator 2602A of the oscillator device is operable to generate third harmonic power (e.g., in the form of current or voltage). The oscillator 2602A may include transistor devices and associated circuitry.

[0113] In some embodiments, the oscillator 2602A includes two transistors, each having a gate, a source, and a drain. These two transistors can be solid-state electronic devices, such as silicon-based solid-state electronic devices. For example, the two transistors can be field-effect transistors (FETs). These two transistors can be arranged (e.g., controlled) to have source, cutoff, and transistor regions to generate third harmonic power. In some embodiments, the two transistors are operatively coupled in phase.

[0114] In some embodiments, oscillator 2602A further includes two gate / drain / source circuits, each transistor having one gate / drain / source circuit (i.e., electrically connected to the respective gate, source, and / or drain of the respective transistor). In some embodiments, the sources of the two transistors are electrically connected to each other, for example, directly. In some embodiments, the gates of the two transistors are electrically connected to each other, for example, directly. In some embodiments, the gate terminals of the two transistors are electrically connected to coupler 2602C. In some embodiments, the gate / drain / source circuit provides a first circuit arrangement electrically connected to the source of the first transistor, a second circuit arrangement electrically connected to the source of the second transistor, a third circuit arrangement electrically connected to the drain of the first transistor and operatively coupled to the patch antenna arrangement 2604, and a fourth circuit arrangement electrically connected to the drain of the second transistor and operatively coupled to the patch antenna arrangement 2604.

[0115] In some embodiments, the first circuit arrangement includes a capacitor for promoting oscillation and a transmission line for power supply. The capacitor and transmission line of the first circuit arrangement may be connected electronically in parallel. In some examples, the capacitor of the first circuit arrangement is grounded. In some examples, the transmission line of the first circuit arrangement is grounded.

[0116] In some embodiments, the second circuit arrangement includes a capacitor for promoting oscillation and a transmission line for power supply. The capacitor and transmission line of the second circuit arrangement may be electronically connected in parallel. In some examples, the capacitor of the first circuit arrangement is grounded. In some examples, the transmission line of the first circuit arrangement is grounded.

[0117] In some embodiments, the structures of the first circuit device and the second circuit device are substantially the same (but connected to different sources of different transistors).

[0118] In some embodiments, the third circuit device includes a transmission line device operatively coupled to the patch antenna device 2604, and an AC short-circuit termination device electrically connected to the transmission line device. In some examples, the AC short-circuit termination device of the third circuit device includes a grounding capacitor device electrically connected to the transmission line device. In some examples, the transmission line device of the third circuit device includes: a first transmission line portion whose end is electrically connected to the AC short-circuit termination device, and a second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device 2604 for capacitively coupled feeding of the patch antenna device. The two transmission line portions may be substantially perpendicular.

[0119] In some embodiments, the fourth circuit device includes a transmission line device operatively coupled to the patch antenna device 2604 and an AC short-circuit termination device electrically connected to the transmission line device. In some examples, the AC short-circuit termination device of the fourth circuit device includes a grounding capacitor device electrically connected to the transmission line device. In some examples, the transmission line device of the fourth circuit device includes: a first transmission line portion whose end is electrically connected to the AC short-circuit termination device, and a second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device 2604 for capacitively coupled feeding of the patch antenna device. The two transmission line portions may be substantially perpendicular.

[0120] In some embodiments, the third circuit device has a structure that is substantially the same as that of the fourth circuit device (but connected to different drains of different transistors).

[0121] Oscillator 2602B, arranged in an oscillator array, can generate third harmonic power (e.g., in the form of current). The structure of oscillator 2602B is basically the same as that of oscillator 2602A. Therefore, the above description of the structure of oscillator 2602A also applies to oscillator 2602B.

[0122] Coupler 2602C of the oscillator device electrically couples two oscillators 2602A and 2602B (therefore, the two oscillators 2602A and 2602B may be referred to as "coupled oscillators"). In some embodiments, coupler 2602C includes an even-mode suppression coupler for enabling or maintaining a non-phase coupling mode between the two oscillators 2602A and 2602B. In some embodiments, the even-mode suppression coupler may include a transmission line device electrically connected between the two oscillators 2602A and 2602B, and a capacitor device electrically connected to the transmission line device and operable to facilitate a short circuit of the even-mode impedance.

[0123] In some embodiments, patch antenna device 2604 includes on-chip patch antenna device.

[0124] In some embodiments, the patch antenna device 2604 includes a plurality of (e.g., two) patch elements, each patch element being operatively coupled to two oscillators 2602A, 2602B, respectively. In some examples, the patch elements are substantially identical in shape, size, and material. Optionally, the patch elements may be portions (e.g., half) of a larger patch. In some embodiments, one patch element is electrically coupled (e.g., capacitively coupled) to a third circuit arrangement of the two oscillators 2602A, 2602B, and the other patch element is electrically coupled (e.g., capacitively coupled) to a fourth circuit arrangement of the two oscillators 2602A, 2602B. In some embodiments, a first transistor of the two oscillators 2602A, 2602B is arranged to selectively or alternately provide third harmonic power to one of the patch elements, while a second transistor of the two oscillators 2602A, 2602B is arranged to selectively or alternately provide third harmonic power to the other patch element.

[0125] Figure 27 A radiator 2700 for terahertz electromagnetic radiation is shown in certain embodiments of the present invention. The radiator 2700 includes a plurality of radiator units 2700-1, 2700-2, 2700-3 operatively coupled to each other. Although Figure 27 Only three radiator units 2700-1, 2700-2, and 2700-3 are shown, but it should be understood that radiator 2700 may include any number (at least one) of radiator units.

[0126] In some embodiments, each of radiator units 2700-1, 2700-2, and 2700-3 may be radiator unit 2500 or radiator unit 2600. Each radiator unit 2700-1, 2700-2, and 2700-3 includes oscillator devices 2702-1, 2702-2, and 2702-3 operably generating third harmonic power (e.g., in the form of current or voltage), and patch antenna devices 2704-1, 2704-2, and 2704-3 operably coupled to the respective oscillator devices 2702-1, 2702-2, and 2702-3 to radiate terahertz electromagnetic radiation based on the third harmonic power generated by the respective oscillator devices 2702-1, 2702-2, and 2702-3. In some embodiments, radiator units 2700-1, 2700-2, and 2700-3 are operatively coupled to operate coherently.

[0127] In some embodiments, radiator 2700 may include a plurality of radiator units arranged in an array having one or more rows. In some embodiments, radiator 2700 may include a plurality of radiator units arranged in an array, each array including at least one radiator unit, all oscillators of all radiator units, forming multiple rows and columns of oscillators. In some embodiments, the array (of the plurality of radiator units) may be divided into multiple subarrays, each subarray having multiple rows, each subarray being able to withstand its own bias voltage, the bias voltage being controllable to affect one or more characteristics (e.g., radiation pattern, direction, etc.) of the terahertz electromagnetic radiation provided by radiator 2700.

[0128] exist Figure 27 In the radiator 2700, radiator units 2700-1 and 2700-2 are arranged in the same row, while radiator units 2700-1 and 2700-3 are arranged in adjacent rows.

[0129] Radiator units 2700-1 and 2700-2 in the same row can be operatively (e.g., electrically) coupled together by a coupling device. In some embodiments, the coupling device includes an even-mode suppression coupler for enabling or maintaining an anti-phase coupling mode between an oscillator of oscillator device 2702-1 of radiator unit 2700-1 and an adjacent oscillator of oscillator device 2702-2 of radiator unit 2700-2. In some embodiments, the even-mode short-circuit coupler of the coupling device may include a transmission line device electrically connecting an oscillator of oscillator device 2702-1 of radiator unit 2700-1 and an adjacent oscillator of oscillator device 2702-2 of radiator unit 2700-2, and a capacitor device electrically connected to the transmission line device and used to facilitate an even-mode impedance short circuit.

[0130] Radiator units 2700-1 and 2700-3 in adjacent rows can be operatively (e.g., electrically) coupled by a coupling device. In some embodiments, the coupling device includes two couplers, one electrically connected between an oscillator of radiator unit 2700-1 and an oscillator of radiator unit 2700-2, and the other electrically connected between another oscillator of radiator unit 2700-1 and another oscillator of radiator unit 2700-2. These two couplers can be odd-mode short-circuit couplers, each used to enable or maintain an in-phase coupling mode between the two oscillators electrically connected to it. In some embodiments, the odd-mode short-circuit coupler may include: a transmission line device electrically connected between a respective oscillator of radiator unit 2700-1 and a respective oscillator of radiator unit 2700-2; a capacitor device electrically connected between the transmission line device and the respective oscillator of radiator unit 2700-1 and operable to facilitate an odd-mode impedance short circuit; and a capacitor device electrically connected between the transmission line device and the oscillator of radiator unit 2700-2 and operable to facilitate an odd-mode impedance short circuit.

[0131] In some embodiments, the radiator 2700 may be fabricated using CMOS technology, such as a 65-nanometer CMOS process / technology. In some embodiments, the radiator 2700 may be disposed in or formed within an integrated circuit (chip). In some embodiments, the radiator 2700 is a terahertz radiator configured solely for terahertz electromagnetic radiation. In some embodiments, the radiator 2700 is configured for terahertz electromagnetic radiation as well as electromagnetic radiation of one or more other frequencies.

[0132] The following disclosure provides further exemplary embodiments of the terahertz electromagnetic radiation radiator and terahertz electromagnetic radiation radiator device of the present invention. These exemplary embodiments can be considered as... Figures 25 to 27 A more specific implementation of the related design.

[0133] In some embodiments, a patch antenna-based two-dimensional array, such as an oscillator array or a coupled oscillator array, is provided. In some embodiments, the patch antenna-based two-dimensional array includes a synchronization network whose operating modes support differential excitation of the patch antenna arrangement of the patch antenna-based two-dimensional array to improve area efficiency. In some embodiments, a coupled oscillator array is provided to achieve high coherent radiated power and lensless effective isotropic radiated power (EIRP). In some embodiments, a high-efficiency and beam-scannable coupled oscillator-radiator array is provided integrated with a patch antenna device for front-side radiation.

[0134] In some embodiments, a two-dimensional synchronization network is provided for a radiator based on an oscillator and a patch antenna. The radiator may include multiple oscillators (e.g., -gm elements) arranged in a two-dimensional array, i.e., multiple rows (multiple oscillators per row) and multiple columns (multiple oscillators per column), and the two-dimensional synchronization network may be configured as a coupled oscillator. The radiator may also include a patch antenna device operatively coupled to the oscillator. The patch antenna device may include a patch antenna differentially fed by two adjacent coupled oscillators.

[0135] In some embodiments, a two-dimensional synchronization network can maintain the anti-phase coupling mode of adjacent coupled oscillators and the in-phase coupling mode of adjacent coupled oscillators in different columns of the same column.

[0136] In this embodiment, the two-dimensional synchronization network can maintain the anti-phase coupling mode of adjacent oscillators (e.g., -gm elements) in each row and the in-phase coupling mode of adjacent oscillators (e.g., -gm elements) in each column (different rows). Combined with a differentially fed patch antenna (which can operate as a power combiner), the anti-phase coupling mode ensures coherent power combining of the oscillators (e.g., -gm elements) in each row. The in-phase coupling mode between rows enables power combining of the entire array.

[0137] To better understand the above design, a two-unit oscillator will be analyzed below to determine the conditions for achieving these two coupling modes.

[0138] Figure 1A A typical two-unit oscillator model is shown. Figure 1A In the middle, Z S and Z L This represents the equivalent input impedance of the two coupled cores. It is worth noting that Z... S or Z L The real part is negative, so they can supplement Z. S and Z L Energy loss between two-port couplers.

[0139] In this example, the two-port coupler is modeled using the Z-parameter. For passive symmetric two-port networks (Z... 11 =Z 22 Z 12 =Z 21 The relationship between voltage and current can be expressed as follows:

[0140]

[0141] The voltage and current of the two cores are represented as follows:

[0142]

[0143] If the two cores oscillate together, then Kirchhoff's Current Law (KCL) should satisfy the following:

[0144]

[0145] According to the above formula, the voltage relationship between the two ports can be expressed as follows:

[0146]

[0147] Z S and Z L The relationship between them can also be deduced as

[0148]

[0149] From another perspective, the Z-parameters can be rewritten using the even-mode and odd-mode impedances of a symmetrical two-port network. Figure 1B The corresponding even-mode and odd-mode equivalent circuits based on the T-type equivalent circuit of a two-port network are shown. From this, it can be inferred that:

[0150]

[0151]

[0152] Furthermore, equations (4) and (5) can be rewritten using even-mode and odd-mode impedances as follows:

[0153]

[0154]

[0155] By shorting the even-mode impedance (Z) e =0), the voltage relationship in equation (8) is equal to -1, and Z L Irrelevant. This corresponds to the anti-coupling mode. Assuming the two cores are identical, the impedance relationship in equation (9) simplifies to Z. S =Z L =-Z o This condition can be used to determine the oscillation frequency and amplitude. Similarly, by shorting the odd-mode impedance (Z... o =0), V1 / V2 = 1. This is equivalent to in-phase coupling mode. Assuming the two cores are identical, the impedance relationship in equation (9) simplifies to Z S =Z L =-Z e .

[0156] Based on the above conclusions, a two-dimensional scalable coupled oscillator array with the desired operating mode can be formed.

[0157] Figure 2The diagram illustrates a two-dimensional scalable coupled oscillator array topology for a terahertz electromagnetic radiation radiator in certain embodiments of the present invention. Figure 2 In each row, an even-mode suppression coupler (“anti-phase coupler”) can be used to maintain an anti-phase coupling mode between two adjacent negative gm (-gm) cells. The even-mode suppression coupler may include a transmission line device electrically connected between two adjacent negative gm cells in the same row, and a capacitor device electrically connected to the transmission line device and used to facilitate a short circuit of the even-mode impedance. In this embodiment, the even-mode short-circuit coupler includes a coupled transmission line electrically connected to two adjacent -gm cells, and a capacitor C2 loaded at the center of the coupled transmission line for short-circuiting the even-mode impedance. In each column, an odd-mode suppression coupler (“non-phase coupler”) can be used to maintain a non-phase coupling mode between two adjacent -gm cells in the same column (and adjacent rows). An odd-mode suppression coupler may include a transmission line device electrically connected between two adjacent -gm units in the same column (and adjacent rows), a first capacitor device electrically connected between the transmission line device and one of the two adjacent -gm units and used to facilitate an odd-mode impedance short circuit, and a second capacitor device electrically connected between the transmission line device and one of the two adjacent -gm units and used to facilitate an odd-mode impedance short circuit. In this embodiment, the odd-mode short-circuit coupler includes a coupled transmission line electrically connected between two adjacent -gm units in the same column (and adjacent rows), a capacitor C1 connecting one of the -gm units and the coupled transmission line, and another capacitor C1 connecting the other -gm unit and the coupled transmission line. In some embodiments, the length of the coupled transmission line is determined, and the capacitance of C1 can then be adjusted to shorten the odd-mode impedance. The odd-mode impedance of the external phase coupler, the even-mode impedance of the internal phase coupler, and the input impedance of the -gm unit should satisfy a derived impedance condition for maintaining oscillation, which can be determined according to the equivalent analysis below.

[0158] Figure 3A and 3B A 12×12 coupled oscillator array 300 (as a radiator of terahertz electromagnetic radiation) is shown in one embodiment of the present invention, the design of which is based on Figure 2 The topology of the two-dimensional scalable coupled oscillator array is shown. Figure 3B A portion of array 300, 300P, has been enlarged. For example... Figure 2 The 12×12 coupled oscillator array 300 comprises 144 oscillators, which are connected by even-mode suppression couplers 320 and odd-mode suppression couplers 310 (for simplicity). Figure 3B (Only one of each coupler is labeled in the text) They are coupled to each other.

[0159] In this embodiment, the oscillators (-gm elements) of array 300 are arranged to collectively oscillate at a fundamental oscillation frequency (f0) of 225 GHz, and the third harmonic (3f0) is radiated using a corresponding differentially fed patch antenna of the patch antenna device (the patch of the patch antenna is not specifically described). In this embodiment, the operating mode of the third harmonic 3f0 is the same as that of the fundamental frequency f0, and horizontally adjacent oscillators can provide anti-phase excitation to the corresponding patch antenna at 3f0. Therefore, the patch antenna can be used as a power combiner to improve area efficiency.

[0160] In this embodiment, the oscillators (-gm elements) of array 300 are arranged to oscillate collectively at a fundamental oscillation frequency (f0) of 225 GHz, and the third harmonic (3f0) is radiated using a corresponding differentially fed patch antenna of the patch antenna assembly (the patch of the patch antenna is not specifically described). In this embodiment, the operating mode of the third harmonic 3f0 is the same as that of the fundamental frequency f0, and horizontally adjacent oscillators can provide out-of-phase excitation to the corresponding patch antenna at 3f0. Therefore, the patch antenna can be used as a power combiner to improve area efficiency.

[0161] In this embodiment, array 300 is divided into four subarrays, each with 3 rows of 12 out-of-phase coupled oscillators (-gm units). Each subarray has its own bias voltage. By adjusting the bias voltages of different subarrays, potential device mismatches in different subarrays can be compensated, thereby achieving forward radiation. Furthermore, by adjusting the bias voltages, the terahertz electromagnetic radiation (such as a beam) radiated by the array can also be redirected. In some embodiments, since the free oscillation frequency of the peripheral oscillators (-gm units) may significantly affect the steady-state phase relationship, the bias voltage V can be adjusted. G1 and / or V G4 To control the direction of radiation on the H-plane.

[0162] Figure 4A and 4B An embodiment of the present invention is shown. Figure 3A The 1×2 element 400 in the 12×12 coupled oscillator array 300. The 1×2 element can be regarded as a radiator element, and the 12×12 coupled oscillator array (with multiple 1×2 elements) can be regarded as a radiator (with multiple radiator elements).

[0163] The unit cell 400 generally includes an oscillator array operable to generate third harmonic power, and a patch antenna array operable to be coupled to the oscillator array to radiate terahertz electromagnetic radiation according to the generated third harmonic power.

[0164] In this embodiment, the unit 400 includes two oscillators, each capable of generating third harmonic power. Each of the two oscillators includes a transistor array 402A and 402B, respectively. The two oscillators have substantially the same structure; therefore, for simplicity, the structure of the oscillator with transistor array 402A will be described in more detail below.

[0165] In this embodiment, the transistor array 402A includes two transistors (e.g., FETs) operatively coupled together and operating in phase, each transistor including its own drain, source, and gate. Each transistor can be arranged (e.g., controlled) to selectively operate and switch between active, cutoff, and transistor regions, thereby facilitating the generation of third harmonic power.

[0166] In this embodiment, the gate terminals of the two transistors are directly electrically connected to each other, and the source terminals of the two transistors are directly electrically connected to each other.

[0167] In this embodiment, the two transistors of transistor arrangement 402A are further connected by various circuit arrangements.

[0168] First, one of the transistors (e.g.) Figure 4A The source of the upper transistor is electrically connected to a capacitor device for promoting oscillation and a transmission line device for power supply. The transmission line device is connected in parallel with the capacitor device. In this embodiment, the capacitor device includes a grounded capacitor, and the transmission line device includes a multi-turn, bent (wavy) transmission line grounded through the capacitor.

[0169] Secondly, another transistor (e.g.) Figure 4A The source of the lower transistor is electrically connected to a capacitor device for promoting oscillation and a transmission line device for power supply. The transmission line device is connected in parallel with the capacitor device. In this embodiment, the capacitor device includes a grounded capacitor, and the transmission line device includes a multi-turn, bent (wavy) transmission line grounded through the capacitor.

[0170] In this embodiment, connected to one of the transistors (e.g. Figure 4A The upper transistor's source capacitor and transmission line are connected to another transistor (e.g., Figure 4A The capacitor and transmission line devices at the source of the lower transistor are roughly the same.

[0171] Third, one of the transistors (e.g.) Figure 4AThe drain of the upper transistor (in the image) is electrically connected to a transmission line device operatively coupled to the patch antenna assembly and an AC short-circuit termination device electrically connected to the transmission line device. In this embodiment, the AC short-circuit termination device includes a grounded capacitor connected in series with the transmission line device. In this embodiment, the transmission line device includes two generally perpendicular straight transmission line portions, one end of a first portion being electrically connected to the AC short-circuit termination device, and a second portion extending from the first portion and electrically coupled to the patch antenna assembly for capacitively feeding the patch antenna assembly. A DC power supply voltage can be applied at the node between the first transmission line portion and the AC short-circuit termination device.

[0172] Fourth, another transistor (e.g.) Figure 4A The drain of the lower transistor in the image is electrically connected to a transmission line device operatively coupled to the patch antenna assembly and an AC short-circuit termination device electrically connected to the transmission line device. In this embodiment, the AC short-circuit termination device includes a grounded capacitor connected in series with the transmission line device. In this embodiment, the transmission line device includes two generally perpendicular straight transmission line sections. One end of the first section is electrically connected to the AC short-circuit termination device, and the second section extends from the first section and is electrically coupled to the patch antenna assembly for capacitively feeding the patch antenna assembly. A DC power supply voltage can be applied to the node between the first transmission line section and the AC short-circuit termination device.

[0173] In this embodiment, connected to one of the transistors (e.g. Figure 4A The transmission line device and AC short-circuit termination device of the drain of the upper transistor in the middle are connected to another transistor (e.g., Figure 4A The transmission line device and AC short-circuit termination device of the lower transistor (in the middle) are roughly the same.

[0174] Similar to the two transistors in transistor array 402A, the two transistors in transistor array 402B are also connected to various circuit devices. These different circuit devices of the two transistors in transistor array 402B are generally the same as those of the two transistors in transistor array 402A. Therefore, for simplicity, they will not be described in detail.

[0175] The cell 400 also includes a coupler 402C that electrically couples the two oscillators. In this embodiment, the coupler 402C is an even-mode suppression coupler (as referenced). Figure 2 The aforementioned coupler is used to enable or maintain an anti-phase coupling mode between the two oscillators. The gates of the transistor arrays 402A and 402B of the two oscillators are electrically connected to an even-mode suppression coupler (and other even-mode suppression couplers connected to adjacent units, if any).

[0176] In this embodiment, one of the transistors (e.g. Figure 4AThe source of the upper transistor in the middle can be coupled to an odd-mode suppression coupler (as shown in reference). Figure 2 The coupler is electrically connected to enable or maintain in-phase coupling mode between itself and an adjacent oscillator in an adjacent cell, and / or another transistor therein (such as...). Figure 4A The source of the lower transistor in the middle can be coupled to an odd-mode suppression coupler (as shown in reference). Figure 2 The coupler is electrically connected to enable or maintain in-phase coupling mode between itself and an adjacent oscillator in an adjacent cell, or another transistor (such as...). Figure 4A The source of the lower transistor in the middle can be coupled to an odd-mode suppression coupler (as shown in reference). Figure 2 The coupler is electrically connected to enable or maintain in-phase coupling mode between itself and adjacent oscillators in adjacent units.

[0177] In this embodiment, the patch antenna device of unit cell 400 includes two patch elements 404A and 404B, which are substantially the same in shape, size, and structure (but arranged in different positions). Each patch element 404A and 404B is coupled to two oscillators respectively. Each patch element 404A and 404B may be part of a larger patch (e.g., combined with patch elements of adjacent cells, as shown in...). Figure 15 ).

[0178] In this embodiment, the patch element 404A is connected to a transistor (e.g., a transistor) of the transistor array 402A. Figure 4A The transmission line of the drain of the upper transistor in the array and the transistor connected to the transistor array 402B (e.g., Figure 4A The upper transistor in the chip has transmission line electrical coupling, particularly capacitive coupling, at its drain. The surface mount element 404A can be differentially fed, meaning that the transistor arrays 402A and 402B can selectively or alternately provide third harmonic power to the surface mount element 404A.

[0179] In this embodiment, the patch element 404B is connected to another transistor (e.g., the transistor array 402A). Figure 4A The transmission line of the drain of the lower transistor in the transistor array 402B, and the transmission line connected to another transistor (e.g., the lower transistor in the transistor array 402B) Figure 4A The lower transistor in the middle is electrically coupled to the drain of the transmission line, especially capacitively coupled. The surface mount element 404B can be differentially fed, that is, the transistor arrays 402A and 402B can selectively or alternately provide third harmonic power to the surface mount element 404B.

[0180] like Figure 4A As shown, in this embodiment, in the plan view, the major axis of the transmission line of coupler 402C (i.e., Figure 4AThe horizontal axis in the diagram can be the reflective symmetry axis of the transmission line arrangement connected to the drain and / or source of one of the transistors, and the transmission line arrangement connected to the drain and / or source of the other transistor in the same transistor arrangement. In this embodiment, from a plan view, the transmission line arrangement of coupler 402C is located between the two surface mount elements 404A and 404B, and the major axis of the transmission line of coupler 402C is the reflective symmetry axis of the two surface mount elements 404A and 404B. In this embodiment, from a plan view, the two oscillators are generally symmetrically arranged around the reflective symmetry axis, which corresponds to the axis that divides each of the two surface mount elements 404A and 404B in two (i.e., Figure 4A (Vertical axis in the middle).

[0181] In one embodiment, the gates of the transistor pairs 402A and 402B are connected to a horizontal coupling network (even-mode short-circuit coupler, intra-unit coupler, or inter-unit coupler) for inverting oscillation / coupling mode. In one embodiment, the sources of the transistor pairs 402A and 402B are connected to a vertical coupling network (odd-mode suppression coupler, inter-unit coupler) for in-phase oscillation / coupling mode. In one embodiment, the sources of the transistor pairs 402A and 402B are respectively connected to their respective parallel capacitors for optimal oscillation and their respective bent transmission lines for DC power supply. In one embodiment, the drains of the transistor pairs 402A and 402B are respectively connected to transmission lines with AC short-circuit terminations. In one embodiment, the DC power supply voltage V for the drains... D Feed is provided via an AC short-circuit terminal. In one embodiment, the capacitor-fed patch antenna device, particularly patch elements 404A and 404B, is operatively coupled to the drain of the transistor pair of transistor devices 402A and 402B to selectively radiate third harmonic power.

[0182] Figure 4B Some example dimensions of unit cell 400 in one embodiment are shown.

[0183] In this embodiment, since the transistor pairs of each transistor arrangement 402A and 402B are connected to the same gate node and source node, the transistor pairs of transistor arrangement 402A operate in phase. The transistor pairs of transistor arrangement 402B operate in phase.

[0184] Figure 5 Showing Figure 4A The equivalent AC superposition circuit at f0 of the quarter circuit of unit cell 400 (based on operating mode). The equivalent AC superposition circuit in this example has an oscillator topology based on T-embedding. In this example, the coupling network can be considered as part of the oscillator. Figure 5In this configuration, the gate inductor is horizontally separated to achieve strong anti-phase coupling, while the source capacitor is vertically separated to achieve weak coupling.

[0185] In some embodiments, to improve conversion efficiency, the harmonic oscillator is specifically designed to optimize the third harmonic output power. The inventors of this invention have realized that the design of an efficient terahertz harmonic oscillator generally involves three aspects: 1) determining the transistor operating state to maximize the desired harmonic output current; 2) oscillator synthesis to meet the obtained conditions; and 3) appropriate impedance matching at the desired harmonic.

[0186] The following section will investigate the nonlinear operating states of transistors to optimize the generation of the third harmonic. By understanding the generation mechanism of the third harmonic current in transistors, the operating conditions for increasing the third harmonic output of transistors can be determined.

[0187] Figure 6 An example simulation setup for studying the nonlinear behavior of transistors is shown. In this example, the simulation frequency is set to 1 GHz to minimize parasitic effects.

[0188] Compared to the nonlinearity of transconductance, the switching of the transistor's operating region can generate much larger harmonic currents at the transistor drain. The inventors of this invention have designed a system where one source of harmonic current is the transition between the active and cutoff regions, and another source is the transition between the active and transistor regions; both transitions can alter the drain current waveform. Within one cycle, the time distribution differences between the active, cutoff, and transistor regions may correspond to different operating states, thus causing variations in the harmonic current. Since other higher harmonics are much weaker, the second and third harmonics will be the focus of the following discussion.

[0189] The DC bias voltage and AC fundamental voltage at the transistor gate primarily determine the duration of the cutoff region. The DC power supply voltage and AC fundamental signal at the transistor drain primarily determine the duration of the transistor's cutoff region.

[0190] Figure 7A The simulated drain current waveform, as well as the gate and drain voltage waveforms, are shown under a given DC bias and fundamental drive voltage. The fundamental waveforms of the gate and drain are not equal, therefore the transistor can output fundamental power. According to... Figure 7A In the settings described, the transistor has been driven to the cutoff region. Then, the fundamental AC voltage at the drain, |V, is changed. d The influence of _f0| on harmonic current output was studied. Figure 7B The corresponding results were displayed. Specifically, Figure 7B This shows the simulated harmonic current at the transistor drain for different fundamental drain voltages, and the current at a selected fundamental voltage |V. d The three corresponding current waveforms at _f0|.

[0191] like Figure 7B As shown in the simulated current waveform, since the transistor enters the triode region, the fundamental current output changes with |V d It decreases as _f0| increases. At high |V d Under the condition of _f0|, the second harmonic current first drops to near zero, then rises. The second harmonic current generated by the transition between the active and cutoff regions is out of phase with the second harmonic current generated by the transition between the active and transistor regions. Therefore, the output second harmonic current will decrease to a very small or minimum value. When the transistor is driven into the deep transistor region, the second harmonic current continues to increase. In this example, it can be observed that the third harmonic current always increases with |V|. d The increase in _f0| is due to the fact that this conversion will increase the generation of third harmonic current.

[0192] If a resistive harmonic load is connected to extract harmonic power, a large harmonic current at the transistor drain will generate a harmonic voltage. This induced harmonic voltage alters the depth of the transistor's region. Therefore, the drain harmonic voltage also changes the harmonic current output. In one example, to study the effect of the second and third harmonic voltages on the output current, phase-correct second and third harmonic voltages are applied to the transistor drain to ensure that the transistor outputs second and third harmonic power to the resistive load. Figure 8A The simulated drain current waveform is displayed (by changing the second harmonic voltage |V). d _2f0| is obtained) and the corresponding gate and drain voltage waveforms obtained from the transistor. Figure 9A The simulated drain current waveform obtained from the transistor is shown (by changing the third harmonic voltage |V) d _3f0| is obtained) and the corresponding gate and drain voltage waveforms.

[0193] Figure 8B This shows the second harmonic drain voltage |V at different transistor drain terminals. d Simulated harmonic current at the transistor drain under _2f0|. Figure 8B In the middle, the harmonic current output is related to different second harmonic voltage amplitudes |V d Corresponding to _2f0|, it can be observed that the fundamental current changes with |V d It increases with the increase of _2f0|. This can be seen from... Figure 8A As can be seen from |V d As _2f0| increases, the current waveform recovers from the sudden drop because the transistor leaves the deep transistor region. For example... Figure 8B As shown, the third harmonic current decreases as the transistor's operating time decreases. As for the second harmonic current, it first decreases to a very small or minimum value, and then increases with ||V. dThe value increases with the increase of _2f0|. This behavior can be understood as the transistor being in the cutoff region. Once the transistor's duration shortens, the cancellation of the second harmonic current generated by the active-transistor switching will decrease. Figure 9B This shows the third harmonic drain voltage ||V at different transistor drain terminals. d Simulated harmonic current at the transistor drain under _3f0|| conditions. Increase ||V d After the amplitude of _3f0||, Figure 9B The harmonic current behavior shown is similar to Figure 9A Similar to the diagram, this also shortens the duration of the transistor's region, restoring the current waveform.

[0194] In summary, the harmonic positive feedback phenomenon used to boost harmonic output in a second-harmonic oscillator can be understood, and this phenomenon also applies to third-harmonic oscillators. For example... Figure 9B As shown, by providing a resistive load to the transistor drain at 3f0, the induced third harmonic voltage V d _3f0 can improve |I d _f0|, thereby increasing the amplitude of the fundamental oscillator. For example... Figure 7B As shown, the improved |V d _f0| can be increased by |Id_3f0|, thus forming a positive feedback loop to boost the third harmonic output power. For example... Figure 9B As shown, |I d _3f0| will follow |V d The value decreases as _3f0| increases, therefore it decreases at high |V. d Under the condition of _3f0|, the loop can eventually remain stable.

[0195] In addition, from Figure 8B It can also be observed that if a second harmonic voltage with appropriate phase is induced at the drain, the third harmonic current will decrease, thereby leading to a decrease in the third harmonic output power. For example... Figure 7B As shown, to mitigate this effect, the generation of second harmonic current can be reduced by simultaneously driving the transistor into cutoff and switching states. Shorting the second harmonic or providing a reactive load at 2f0 to change the phase of the induced voltage can also alleviate the problem of current drop at 3f0.

[0196] In summary, a large fundamental drive voltage at the transistor gate and drain can improve the generation of third harmonic current. Applying an appropriate resistor to the transistor drain during third harmonic operation helps improve third harmonic output and harmonic power extraction. Furthermore, minimizing the second harmonic current can prevent a reduction in third harmonic current output.

[0197] The previous section investigated the nonlinear operation of transistors at low frequencies and introduced methods to improve the generation of third harmonic currents. Considering the parasitic capacitance of transistors, the design of a 225GHz high-frequency oscillator will be presented below.

[0198] As described above, by driving the transistor to the cutoff region to generate a high fundamental amplitude harmonic at the transistor gate, and by driving the transistor to the transistor region to generate a high fundamental amplitude harmonic at the transistor drain, the third harmonic current output can be increased simultaneously. The higher net fundamental output power of the transistor can maintain a stronger fundamental amplitude in the oscillator. In some examples, the fundamental voltage gain phase difference between the gate and drain is deviated by 180° to compensate for the phase deviation caused by the DC feedthrough, thereby increasing the fundamental oscillation amplitude at the fundamental oscillation frequency.

[0199] Figure 10 An example simulation setup is shown for determining the fundamental operating conditions and harmonic load impedance (fundamental frequency set to 225 GHz). Specifically, Figure 10 The simulation settings can be used to determine the optimal fundamental voltage gain phase difference and the corresponding net fundamental output power Po_f0.

[0200] Figure 11A The simulated net fundamental output power Po_f0 is shown for different fundamental voltage gain phase differences φ. For example... Figure 11A As shown, in this example, a phase difference of approximately 160° maximizes Po_f, resulting in a higher fundamental oscillation amplitude.

[0201] In one example, driving the transistor to the cutoff and triode regions can eliminate second harmonic currents and mitigate the potential adverse effects of drain-induced second harmonic voltages without short-circuiting it, thus simplifying circuit design.

[0202] In one example, the gate bias voltage V G The fundamental voltage V applied to the gate is selected as 0.9V. g _f0 is 1.2V, which will drive the transistor into the cutoff region. Then, the supply voltage V D Select 1.4V, and utilize Figure 10 The example simulation in the example is set at the drain (V d _f0) sweep frequency fundamental voltage.

[0203] The generated second and third harmonic currents and the transistor's net fundamental output power are as follows: Figure 11B As shown. Specifically, Figure 11B This shows the different fundamental voltages |V at the drain of the transistor. d Under the condition of _f0|, the simulation generates second and third harmonic currents and the net fundamental output power of the transistor.

[0204] The results showed that, in this example, by making V d When _f0 = 1.0V, the transistor can also be driven into the triode region to cancel the second harmonic current, which is close to its minimum. Coincidentally, at V d When _f0 = 1.0V, Po_f0 is close to its peak value. Based on the determined fundamental drive voltage, the corresponding current can be obtained using the same simulation settings. Given the oscillator topology, the corresponding component values ​​can be explicitly synthesized based on the obtained voltage and current. Oscillator topologies based on T-embedded networks can be used for terahertz harmonic oscillator design. In one example, the calculated component values ​​are labeled on the equivalent AC superposition circuit, such as... Figure 5 As shown.

[0205] At low frequencies, providing a suitable resistive load to the transistor drain at the 3f0 position allows for the extraction of third harmonic power from the transistor. As mentioned earlier, this also generates a phase-correct harmonic voltage, which, due to the harmonic positive feedback phenomenon of the harmonic oscillator, can improve output power. At terahertz frequencies, the optimal drain-source impedance at 3f0 should be inductive to resonate with the transistor's parasitic capacitance, thus providing a resistive load. Therefore, good impedance matching at 3f0 is particularly useful as it effectively extracts harmonic power and improves output. In one example, using... Figure 10 The optimal impedance can be determined by performing harmonic load traction simulation. Under a defined bias voltage and fundamental voltage, the third harmonic drain-source impedance Z is scanned. ds _3f0. The corresponding output power is as follows: Figure 12 As shown in the figure, the transistor exhibits different third harmonic drain-source impedances Z. ds The third harmonic output power Po_3f0 at 3f0. In this example, for the peak third harmonic output power Po_3f0, the optimal Z... ds _3f0 is approximately 8+j17Ω. Figure 10 Other harmonic impedances shown are initially determined to be optimal Z. ds Set _3f0 to zero, and finally set it according to the actual value of the implementation design.

[0206] Regarding the topology preference for 3f0 extraction, in some implementations, a synthesized T-embedded network oscillator topology is used because it naturally separates the gate and drain bias voltages, which can be easily tuned to optimal fundamental oscillation conditions to improve third harmonic output. Furthermore, this topology is also suitable for high-efficiency third harmonic extraction. Figure 5 As shown, in some embodiments of this topology, there is no explicit path to guide the third harmonic current to the lossy gate, thus the harmonic current feedback loss can be easily reduced.

[0207] However, in some examples, implicit third harmonic currents may still be fed back to the gate through parasitic gate-drain or gate-source capacitance.

[0208] Figure 13 Showing Figure 4B The equivalent AC superposition circuit of a quarter circuit in the 1×2 unit at 3f0. For example... Figure 13 As shown, the third harmonic current generated within the transistor is simulated as a current source. If the source impedance at 3f0 is very small, the 3f0 current will flow directly to ground instead of through C. gs Loss resistance R flowing back to the gate g On the other hand, if the impedance of the gate termination at 3f0 is large enough, then through C... gd Flow to R g The 3f0 current will also decrease. For example Figure 13 As shown, in one implementation of the topology, the source terminal is connected to a capacitor, which naturally has a low impedance at 3f0. The gate terminal at 3f0 has a relatively large equivalent impedance. The simulated power loss at the lossy gate resistance 3f0 is approximately 1μW, far lower than that at close to 1μW. Figure 12 The simulated power at the mid-peak value (approximately 140 μW).

[0209] As mentioned earlier, good impedance matching helps to efficiently deliver high power to the antenna. Based on the optimal Z obtained in the above disclosure... ds _3f0, in de-embedding Figure 13 Z shown ds After _3f0, the antenna impedance should be adjusted to approximately 6.4 + j23Ω.

[0210] In one embodiment, the following was used Figure 4A and Figure 4B The capacitor-coupled antenna feeding method is shown. By adjusting... Figure 4B The required input impedance can be easily obtained from the l and ds of the transmission line section shown.

[0211] Figure 14A This displays the input impedance of the final design, i.e. Figure 4A The simulated input impedance of the patch antenna in unit 400 at 3f0. Figure 14B show Figure 4A The simulated gain of the patch antenna in element 400 at f0 and 3f0. For example... Figure 14A As shown, small coupling capacitors can be used to suppress fundamental radiation, as evidenced by the difference in array simulation gain. In one design example, a significant gain difference of approximately 36 dB can be achieved.

[0212] According to the above embodiments (especially) Figure 2-4BA 12×12 coupled oscillator array and a 1×2 cell were designed and fabricated using a 65-nanometer CMOS process.

[0213] Figure 15 Showing according to Figure 3A Micrograph of an integrated circuit (chip) made of a 12×12 coupled oscillator array. Figure 16 Showing according to Figure 4A A micrograph of a 1×2 cell (coupled oscillator array) integrated circuit (chip) fabricated using 1×2 cells. In this example, the overall chip size of the 12×12 coupled oscillator array is 2mm × 1.7mm, and the core area is 1.8mm × 1.5mm.

[0214] Figure 17 This shows an example measurement setup for measuring the frequency, radiation pattern, and equivalent isotropic radiated power (EIRP) of fabricated chips (arrays and unit cells). Figure 17 In the example measurement setup, a VDI WR1.5 SAX mixer (Virginia Diodes) is connected to a Keysight signal analyzer N9041B (Keysight Technologies) to detect the radiated signal from a chip (12×12 coupled oscillator array) received by a VDI WR1.5 diagonal horn antenna (Virginia Diodes). Figure 17 As shown, an absorber is covered on the metal plate in front of the mixer to avoid multiple reflections.

[0215] Figure 19A The measured spectrum of the 12×12 coupled oscillator array chip at a frequency of 674.85 GHz is shown. The output frequency can be adjusted by changing the power supply and bias voltage. Figure 19B Showing with Figure 15 Simulation and measurement of the frequency adjustment range related to the 12×12 coupled oscillator array. For example... Figure 19B As shown, the tuning range from 643 GHz to 689 GHz is 6.9%. It is worth noting that... Figure 19B The bias voltage shown is for one subarray in the array. The bias voltages of the other subarrays are slightly adjusted to ensure that the radiated terahertz electromagnetic radiation beam is in the wide side direction.

[0216] When measuring EIRP and radiated power, the beam must also be adjusted to radiate in the forward direction. During the measurement, the distance between the 12×12 coupled oscillator array chip and the horn antenna was approximately 30 cm, satisfying the far-field condition. Path loss, mixer conversion loss, and cable loss were accounted for. Figure 18 The example calibration device in the example is used for calibration. Figure 20Showing Figure 15 Simulation and measurement of equivalent isotropic radiated power (EIRP) of a 12×12 coupled oscillator array chip.

[0217] In this embodiment, the chip of the 12×12 coupled oscillator array radiates from the front via a patch antenna device. Therefore, the chip can be thermally coupled to a thermal management device on the other side (e.g., the back side) to regulate its temperature. In this example, the chip is directly connected to the radiator for heat dissipation. Figure 17 As shown, in this embodiment, a thermoelectric cooler and a fan are further used to more effectively transfer the heat of the chip and reduce the operating temperature.

[0218] Figure 17 The two thermal images in the image compare the operating temperature of a 12×12 coupled oscillator array chip at peak power using two different cooling methods (one method uses only a radiator (lower thermal image), and the other uses a radiator along with a thermoelectric cooler and a fan (upper thermal image)). Figure 20 As shown, lowering the operating temperature increases output power, thereby improving EIRP. In this example, by using a thermoelectric cooler and a fan, the EIRP can be improved by approximately 2 dBm. In this example, the measured peak EIRP at 674.9 GHz is 30.8 dBm.

[0219] In one measurement, the phase noise was directly measured using a spectrum analyzer. Figure 21A The phase noise measurement of the 12×12 coupled oscillator array chip at 675 GHz is shown. Figure 21B The phase noise measurements at different frequencies with a 1MHz offset are shown. For comparison, the phase noise performance of the fabricated 1×2 cell was also measured, with results at different frequencies also shown. Figure 21B As shown, it can be seen that the phase noise improvement of the 12×12 array is close to the theoretical value compared to the 1×2 unit cell.

[0220] Figure 17 The electric rotary table in the measuring device is used to facilitate the measurement of radiation patterns.

[0221] Figure 22A The simulated and measured radiation patterns (E-plane and H-plane modes) of a 12×12 coupled oscillator array chip at 675 GHz are shown. It can be seen that the results are in excellent agreement, especially the E-plane pattern. In this example, due to the high coupling strength of the coupled oscillator array in the E-plane, the phase error caused by device mismatch is not significant, thus the array can maintain a relatively ideal anti-phase coupling mode in this plane. Conversely, in this example, due to the smaller injected current, the coupling strength of the in-phase coupling mode is weaker, such as... Figure 5 The equivalent circuit is shown in the figure.

[0222] Based on the E-plane and H-plane patterns measured at different frequencies, the corresponding directivity is calculated and compared with the simulation values. Figure 22B The simulated and calculated directivity of a 12×12 coupled oscillator array chip are shown. It was found that the directivity calculated from the two measured planes is approximately 1 dB lower than the corresponding simulated values, which is consistent with... Figure 22A The good matching results shown are different. In this example, the simulated directivity is calculated based on the entire three-dimensional radiation field distribution, but the calculated directivity is only the average of two measurement planes, which may introduce errors, especially when the beamwidths of the two planes are different. Therefore, using simulated directivity to calculate radiated power would be more accurate; in this example, a simulated directivity of 21.7 dB at 670 GHz is used. Then, the measured radiated power of the 12×12 coupled oscillator array chip is calculated, as follows: Figure 23A As shown. The peak radiated power is 9.1 dBm at 674.9 GHz. Figure 23B The simulated and measured power consumption of a 12×12 coupled oscillator array chip are shown. The results indicate that, at the same supply voltage, the simulated DC power consumption is higher than the measured value, while at V... D Measurement power consumption at 1.4V and V D The simulation results at 1.2V are close. This is likely due to the voltage drop in the bond wires, as the DC current can be as high as 2.6A. In this example, the supply voltage V... D The measurements were taken on a printed circuit board (PCB), and voltage drops in the bonding wires will result in a smaller voltage applied to the transistor. Besides model inaccuracies, voltage drop issues could also be a cause of discrepancies between simulated and measured EIRP.

[0223] In this embodiment, the peripheral subarray (V) is adjusted. G1 or V G4 The bias voltage can effectively change the stable phase relationship, such as Figure 24A The simulation phase is shown in the figure, where V G4 The voltage is set to 0.8V, with the remaining subarrays maintained at 1V. Therefore, the radiation beam in the H-plane can be redirected. In the measurement, V... G2 and V G3 With slight adjustments, the measured radiation pattern and corresponding bias configuration are as follows: Figure 24B and Figure 24C As shown. In this example, the radiation beam on the H-plane can scan from -45° to +45° (attenuation of 5dB).

[0224] The above embodiments of the present invention provide a two-dimensional scalable array based on differential feeding and patch antennas, featuring beamforming capabilities and high DC-Terahertz conversion efficiency. One example embodiment of the present invention provides a 12×12 coupled oscillator array chip with an area of ​​2mm×1.7mm, operating between 643GHz and 689GHz (6.9%), exhibiting a peak radiated power of 9.1dBm and a power consumption of 3.32-W (meaning a DC-Terahertz conversion efficiency of 0.245% at 675GHz). In this example embodiment, the corresponding EIRP without external lens is 30.8dBm, and the measured phase noise at a 1MHz offset is -90.9dBc / Hz. In this example embodiment, the beam can be steered from -45° to 45° in the H-plane. Table I lists various performance characteristics and features of the silicon coherent terahertz radiator array in one example embodiment of the present invention. This invention provides a high-frequency beam-steerable integrated circuit, namely a silicon-based coherent terahertz radiator array with a frequency exceeding 300 GHz, which can efficiently radiate high power and EIRP.

[0225] Therefore, after describing several embodiments, those skilled in the art will recognize that different modifications, alternative structures, and equivalents can be used without departing from the essence of the invention. Accordingly, the above description should not be construed as limiting the scope of the invention as defined in the following claims.

[0226] Table I – Performance or characteristics of a silicon coherent terahertz radiator array in one embodiment

[0227]

[0228] Some embodiments of the present invention provide a large-scale coherent terahertz (THz) source array with multiple coupled oscillator elements. Some embodiments of the present invention provide a two-dimensional scalable coupled topology suitable for large array formation to achieve desired coherent oscillation modes, wherein a differential patch antenna can be incorporated to radiate the third harmonic without the need for lenses, achieving high output frequencies exceeding 600 GHz. Part of the disclosure relates to the study of nonlinear transistor operation to find optimal operating states to improve the third harmonic output. Part of the disclosure relates to designing the oscillator based on the determined optimal states. In some embodiments of the present invention, the input impedance of the antenna is matched to the optimal value for harmonic boosting and efficient harmonic power extraction by the transistor. The design in some embodiments of the present invention enables beam steering by varying the bias voltage to establish different phase gradients throughout the array.

[0229] Some embodiments of the present invention may include one or more of the following example functions and applications. For example, some embodiments of the present invention provide a high-power terahertz electromagnetic radiation source that can be used in terahertz applications such as high-speed wireless data transmission, spectroscopy, imaging, and radar. For example, some embodiments of the present invention use relatively low-cost CMOS technology to generate and radiate high-power, high-frequency terahertz signals. For example, some embodiments of the present invention can be implemented as part of an active terahertz imaging system to illuminate a target object, and beam steering functionality can shorten imaging time. Some embodiments of the present invention provide a terahertz source with a steerable radiation beam. Some embodiments of the present invention can be used for 5G, 6G, or higher wireless communications, for example, for data transmission at data rates exceeding 100 Gbps. Some embodiments of the present invention can be used for terahertz imaging. Some embodiments of the present invention can replace existing commercial terahertz extenders as signal sources. It should be noted that some embodiments of the present invention may include one or more additional or alternative functions and / or applications not specifically described or illustrated.

[0230] Certain embodiments of the present invention may include one or more of the following example advantages. For example, the radiator elements or radiators in some embodiments may provide better DC-to-terahertz conversion efficiency. For example, the topology of the radiator element arrays in some embodiments of the present invention may be scalable or suitable for implementing large-scale arrays. It should be noted that certain embodiments of the present invention may include one or more additional or alternative advantages not specifically described or illustrated.

[0231] The radiator of this invention can be provided or included in an integrated circuit. The integrated circuit can be included in a device. A device with a radiator may also include a thermal management device thermally coupled to the radiator for regulating the temperature of the radiator (e.g., for promoting heat dissipation from the radiator). For example, the thermal management device may be coupled to one side (e.g., the back side) of the integrated circuit. For example, the thermal management device may include passive thermal management devices (e.g., radiators with heat sinks, pins, etc.) and / or active thermal management devices (e.g., fans, liquid-based heat exchangers, evaporative heat exchangers, etc.). A device with a radiator may lack any lenses relative to the radiator assembly to influence (e.g., enhance) the directivity of the terahertz electromagnetic radiation provided by the radiator. The radiator, integrated circuit, or device can be included in a system providing terahertz electromagnetic radiation. This system can be a sensing system, a communication system, a spectral system, an imaging system, etc. The system can be an active terahertz imaging system for illuminating an object (e.g., a target object). The system can be a cellular (e.g., 5G, 6G, 6G+, or similar) communication system.

[0232] Those skilled in the art will understand that variations and / or modifications can be made to the described and / or illustrated embodiments of the present invention to provide other embodiments of the invention. Therefore, the embodiments described and / or illustrated in this invention should be considered exemplary in all respects and not restrictive. Examples of optional features of certain embodiments of the invention are provided in the abstract and description. Some embodiments of the invention may include one or more of these optional features. Some embodiments of the invention may lack one or more of these optional features. For example, one or more shapes, sizes, configurations, orientations, etc., of a component.

Claims

1. A radiator for terahertz electromagnetic radiation, comprising: One or more radiator units, each of the radiator units comprising: An oscillator device operable to generate third harmonic power; the oscillator device includes: Operable as a first oscillator to generate third harmonic power; Operable as a second oscillator to generate third harmonic power; and A coupler electrically coupling the first oscillator and the second oscillator; wherein the coupler includes an even-mode suppression coupler for enabling or maintaining an anti-phase coupling mode between the first oscillator and the second oscillator; and A patch antenna device operably coupled to the oscillator device is used to radiate terahertz electromagnetic radiation according to the generated third harmonic power.

2. The radiator according to claim 1, wherein the even-mode suppression coupler comprises: A transmission line device electrically connected between the first oscillator and the second oscillator, and A capacitor device electrically connected to the transmission line device and operable to facilitate a short circuit of the even-mode impedance.

3. The radiator of claim 1, wherein the first oscillator and the second oscillator are arranged to differentially feed the patch antenna device.

4. The radiator of claim 1, comprising a plurality of said radiator units operatively coupled to each other.

5. The radiator of claim 4, wherein the plurality of radiator units at least includes a first radiator unit and a second radiator unit arranged in the same row; and The radiator includes a coupling device that electrically couples the first radiator unit and the second radiator unit.

6. The radiator of claim 4, wherein the plurality of radiator units comprises at least a first radiator unit and a second radiator unit arranged in adjacent rows; and in, The radiator includes a coupling device that electrically couples the first radiator unit and the second radiator unit in adjacent rows.

7. The radiator according to claim 4, The plurality of radiator units are arranged in an array having multiple rows, each row including at least one radiator unit; The array described herein comprises multiple subarrays, each subarray comprising a portion of multiple rows; Each of the plurality of subarrays is arranged to withstand its own bias voltage.

8. An integrated circuit comprising at least one radiator according to claim 1.

9. A radiator for terahertz electromagnetic radiation, comprising: One or more radiator units, each of the radiator units comprising: An oscillator device operable to generate third harmonic power; and A patch antenna device operably coupled to the oscillator device for radiating terahertz electromagnetic radiation according to the generated third harmonic power; The oscillator device includes: Operable as a first oscillator to generate third harmonic power; Operable as a second oscillator to generate third harmonic power; and Each of the first oscillator and the second oscillator includes: A first transistor having a gate, a source, and a drain; and A second transistor having a gate, a source, and a drain; The first transistor and the second transistor are operatively coupled to operate in phase.

10. The radiator of claim 9, wherein the gate of the first transistor and the gate of the second transistor are electrically connected to each other; and / or The source of the first transistor and the source of the second transistor are electrically connected to each other.

11. The radiator of claim 9, wherein each of the first oscillator and the second oscillator further comprises: A first circuit device electrically connected to the source of the first transistor; A second circuit device electrically connected to the source of the second transistor; A third circuit device electrically connected to the drain of the first transistor and operatively coupled to the patch antenna device. as well as A fourth circuit device electrically connected to the drain of the second transistor and operatively coupled to the patch antenna device.

12. The radiator of claim 11, wherein the first circuitry comprises: Capacitor devices used to promote oscillation; as well as Transmission line device for power supply; In this circuit, the capacitor device and the transmission line device are connected in parallel.

13. The radiator according to claim 12, in, The capacitor device of the first circuit device is grounded; and The transmission line device of the first circuit device is grounded and includes a bent transmission line.

14. The radiator of claim 11, wherein the second circuit device comprises: Capacitor devices used to promote oscillation; as well as Transmission line device for power supply; In this circuit, the capacitor device and the transmission line device are connected in parallel.

15. The radiator according to claim 14, in, The capacitor device of the second circuit arrangement is grounded; and The transmission line device of the second circuit device is grounded and includes a bent transmission line.

16. The radiator of claim 11, wherein the third circuit device comprises: A transmission line device operatively coupled to the patch antenna device; as well as An AC short-circuit termination device electrically connected to the transmission line device.

17. The radiator of claim 16, wherein the transmission line device of the third circuit device comprises: The first transmission line portion has one end electrically connected to the AC short-circuit termination device so as to apply a DC power supply voltage between the first transmission line portion and the AC short-circuit termination device. as well as A second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device is used to capacitively feed the patch antenna device.

18. The radiator of claim 11, wherein the fourth circuit device comprises: A transmission line device operatively coupled to the patch antenna device; as well as An AC short-circuit termination device electrically connected to the transmission line device.

19. The radiator of claim 18, wherein the transmission line device of the fourth circuit device comprises: The first transmission line portion has one end electrically connected to the AC short-circuit termination device so as to apply a DC power supply voltage between the first transmission line portion and the AC short-circuit termination device. as well as A second transmission line portion extending from the first transmission line portion and electrically coupled to the patch antenna device is used to capacitively feed the patch antenna device.

20. The radiator of claim 11, wherein the patch antenna assembly comprises: A first patch element operatively coupled to the first oscillator and the second oscillator; as well as A second patch element operatively coupled to the first oscillator and the second oscillator.

21. The radiator according to claim 20, in, The first surface mount element is electrically coupled to the third circuitry of the first oscillator and the third circuitry of the second oscillator; and / or The second surface mount element is electrically coupled to the fourth circuit device of the first oscillator and the fourth circuit device of the second oscillator.

22. The radiator according to claim 21, in, The first transistor of the first oscillator and the first transistor of the second oscillator are arranged to selectively or alternately provide third harmonic power to the first patch element; and / or The second transistor of the first oscillator and the second transistor of the second oscillator are arranged to selectively or alternately provide third harmonic power to the second patch element.

23. A radiator for terahertz electromagnetic radiation, comprising: One or more radiator units, each of the radiator units comprising: An oscillator device operable to generate third harmonic power; and A patch antenna device operably coupled to the oscillator device for radiating terahertz electromagnetic radiation according to the generated third harmonic power; The oscillator device includes: Operable as a first oscillator to generate third harmonic power; Operable as a second oscillator to generate third harmonic power; and A coupler that electrically couples the first oscillator and the second oscillator; The one or more radiator units comprise a plurality of radiator units operably coupled to each other; the plurality of radiator units include at least a first radiator unit and a second radiator unit arranged in the same row; and The radiator includes a coupling device that electrically couples the first radiator unit and the second radiator unit; and The coupling device includes an even-mode suppression coupler for enabling or maintaining an anti-phase coupling mode between (i) the first oscillator of one of the first radiator units and the second radiator unit, and (ii) the second oscillator of the other of the first radiator unit and the second radiator unit.

24. The radiator of claim 23, wherein the even-mode short-circuit coupler of the coupling device comprises: A transmission line arrangement electrically connected between (i) the first oscillator of one of the first radiator units and (ii) the second oscillator of the other of the first radiator units; and A capacitor device electrically connected to the transmission line device and operable to facilitate a short circuit of the even-mode impedance.

25. A radiator for terahertz electromagnetic radiation, comprising: One or more radiator units, each of the radiator units comprising: An oscillator device operable to generate third harmonic power; and A patch antenna device operably coupled to the oscillator device for radiating terahertz electromagnetic radiation according to the generated third harmonic power; The oscillator device includes: Operable as a first oscillator to generate third harmonic power; Operable as a second oscillator to generate third harmonic power; and A coupler that electrically couples the first oscillator and the second oscillator; The one or more radiator units comprise a plurality of radiator units operably coupled to each other; the plurality of radiator units include at least a first radiator unit and a second radiator unit arranged in adjacent rows; and The radiator includes a coupling device that electrically couples the first radiator unit and the second radiator unit; The coupling device includes: A first coupler electrically connected between the first oscillator of the first radiator unit and the first oscillator of the second radiator unit, and A second coupler electrically connected between the second oscillator of the first radiator unit and the second oscillator of the second radiator unit.

26. The radiator according to claim 25, in, The first coupler includes a first odd-mode short-circuit coupler for enabling or maintaining an in-phase coupling mode between the first oscillator of the first radiator unit and the first oscillator of the second radiator unit; and The second coupler includes a second odd-mode short-circuit coupler for enabling or maintaining the in-phase coupling mode between the second oscillator of the first radiator unit and the second oscillator of the second radiator unit.

27. The radiator of claim 26, wherein the first odd-mode short-circuit coupler comprises: A transmission line device electrically connected between the first oscillator of the first radiator unit and the first oscillator of the second radiator unit; A first capacitor device electrically connected between the transmission line device and the first oscillator of the first radiator unit is operable to facilitate a short circuit of the odd-mode impedance. as well as A second capacitor device electrically connected between the transmission line device and the first oscillator of the second radiator unit is operable to facilitate a short circuit of the odd-mode impedance.

28. The radiator of claim 26, wherein the second odd-mode short-circuit coupler comprises: A transmission line device electrically connected between the second oscillator of the first radiator unit and the second oscillator of the second radiator unit; A first capacitor device electrically connected between the transmission line device and the second oscillator of the first radiator unit is operable to facilitate a short circuit of the odd-mode impedance. as well as A second capacitor device electrically connected between the transmission line device and the second oscillator of the second radiator unit is operable to facilitate a short circuit of the odd-mode impedance.

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