Differential broadband quadrature signal generation using over-coupled directional couplers

Abstract

Embodiments herein relate to quadrature signal generation and to broadband differential quadrature signal generation at millimeter wave frequencies using over-coupled directional couplers. In an example, a quadrature signal generating sub-circuit (125) includes two conductive strips arranged parallel to each other on different layers of metal interconnects of a substrate (i.e., during a CMOS manufacturing process), the two conductive strips forming a directional coupler. Each conductive strip has a length and a width configured such that an input end of a first conductive strip and a coupling end of a second conductive strip generate an overcoupling factor, the input end being electromagnetically coupled together with the coupling end. The input may be configured to be coupled to a local oscillator (120), and the coupling may be configured to be coupled to a mixer (e.g., a mixer (115), a mixer (116)). The directional coupler may provide an output of a desired bandwidth to the one or more mixers based on the overcoupling factor.

Description

Technical Field

[0001] This relates generally to radio frequency signal generation, and more particularly to the use of quadrature signal generators to generate a wideband output. Background Art

[0002] Radio frequency (RF) signal generation circuits are employed across a wide range of application areas, including telecommunications, telemetry, aerospace applications, wireless data transmission, satellite and radar imaging, etc. RF signal generation circuits can be used to interface with a transmitter or receiver and generate two signals based on a signal from a local oscillator: one with a real value and the other with a virtual value. The two signals can be 90 degrees out of phase with respect to each other, which can provide benefits in processing data received and transmitted by an antenna in such application areas.

[0003] Various applications can use signal generation components integrated on a system on chip (SoC) to perform orthogonal signal generation. In order to generate in-phase and 90-degree out-of-phase signals, passive structures, such as couplers, can be formed in metal layers deposited onto a silicon substrate. There are many passive structures to generate real and virtual signals, however, such structures may only generate signals with fractional bandwidths (e.g., 10 to 15%) at millimeter-wave frequencies. Therefore, these couplers are generally only usable for certain applications that operate only within a narrow bandwidth. In order to accommodate bandwidth constraints, some solutions may include digital circuit systems to adjust and reconfigure the bandwidth output of the system. However, such solutions increase system complexity, design area requirements, and design costs. In addition, reconfiguring the frequency band using digital circuit systems may cause the output signal to switch from one frequency band to another, rather than increasing the overall bandwidth range. Summary of the invention

[0004] Various embodiments disclosed herein relate to differential orthogonal signal generation, and more specifically, to generating broadband differential orthogonal signals at millimeter wave frequencies using an overcoupled directional coupler. In the orthogonal signal generator, conductive strips can be arranged in parallel relative to each other and arranged on different metal layers deposited on a silicon substrate to form a directional coupler (e.g., on a metal interconnect deposited on a silicon substrate). Each conductive strip has a selectively selected length and width so that an input end of a first conductive strip in a pair of strips and a coupling end of a second conductive strip in the pair of strips generate an overcoupling factor, and the input end is electromagnetically coupled to the coupling end. The input end can be coupled to or connected to a local oscillator, and the coupling end and the through end can be configured to be coupled to or connected to an orthogonal mixer and an in-phase mixer, respectively. The directional coupler can provide an output of a desired bandwidth (e.g., an in-phase or quadrature clock) to the mixer based on the overcoupling factor.

[0005] In one example, a system is provided. The system includes a first amplifier, a first mixer, a second mixer, a local oscillator, an orthogonal signal generation subcircuit, a second amplifier, a third amplifier, a first analog-to-digital converter (ADC), and a second ADC. The first amplifier is configured to be coupled to an antenna. The first and second mixers are coupled to the first amplifier. The orthogonal signal generation subcircuit is coupled to the first mixer, the second mixer, and the local oscillator. The second amplifier is coupled to the first mixer, and the third amplifier is coupled to the second mixer. The first ADC is coupled to the second amplifier, and the second ADC is coupled to the third amplifier. The orthogonal signal generation subcircuit includes: a first conductive strip having a first width and a first length, arranged in a first layer of an interconnect of a substrate (e.g., a first metal layer on a silicon substrate); and a second conductive strip having a second width and a second length, arranged in a second layer of the interconnect. The first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect, so that the first conductive strip and the second conductive strip form a directional coupler. The first conductive strip includes: a first end, which is configured to be coupled to a local oscillator; and a second end, which is opposite to the first end. The second conductive strip includes: a third end configured to be coupled to the first hybrid and electromagnetically coupled to the first end; and a fourth end opposite to the third end. The first length of the first conductive strip and the second length of the second conductive strip are based on a quarter wavelength of a center frequency of a bandwidth of the directional coupler. In addition, the first width of the first conductive strip and the second width of the second conductive strip are configured to generate a coupling gain between the first end and the third end of the directional coupler. The coupling gain between the first end of the first strip and the first end of the third strip may be greater than the throughput gain between the first end and the second end of the first conductive strip.

[0006] This summary is provided to introduce in simplified form a series of concepts that are further described in the detailed description below. It is understood that this summary is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 An operating environment for orthogonal signal generation that may be used according to an embodiment is described.

[0008] Figure 2A , 2B 2C illustrate aspects of conductive features used in a quadrature signal generation subcircuit according to an embodiment.

[0009] The drawings are not necessarily drawn to scale. In the drawings, like reference numerals represent corresponding parts throughout the several views. In some embodiments, components or operations may be separated into different blocks or may be combined into a single block. DETAILED DESCRIPTION

[0010] Discussed herein are enhanced components, techniques and systems related to orthogonal signal generation, and more specifically to generating fully differential broadband orthogonal signals at millimeter wave frequencies using overcoupled directional couplers. In an orthogonal signal generator, a local oscillator can generate a local oscillator signal that is substantially sinusoidal and has a given frequency. The local oscillator can be coupled to a set of mixers via a directional coupler. An example directional coupler is a passive device that includes conductive strips arranged in parallel with each other and arranged on different metal layers of an interconnect of a silicon substrate, for example, via a complementary metal oxide semiconductor (CMOS) manufacturing process, the passive device generates two local oscillator signals, one local oscillator signal for each mixer, the two local oscillator signals having substantially equal power and being 90° out of phase with respect to each other (e.g., an in-phase local oscillator signal and an orthogonal local oscillator signal).

[0011] Each conductive strip has a length and width that are selectively selected so that an input end of a first conductive strip in a pair of strips and a coupled end of a second conductive strip in the pair of strips generate an overcoupling factor, and the input end is electromagnetically coupled with the coupled end. Due to the passive nature, many directional couplers only provide a suitable local oscillator signal to a mixer when the local oscillator signal frequency falls within a very narrow frequency range for which the coupler is optimized. However, some examples of the present disclosure provide a directional coupler that provides a suitable local oscillator signal over a wide frequency range (e.g., with a bandwidth) based on an overcoupling factor, thereby allowing the same directional coupler design to be used in products that support multiple local oscillator signal frequencies and can be used in different products without redesign (e.g., a directional coupler design that can be used in 60 GHz radar and 80 GHz radar products).

[0012] In contrast, existing coupling devices may only generate signals of a specific bandwidth and within approximately 10 to 15% of the fractional bandwidth relative to the center frequency. Therefore, for applications requiring wider bandwidths or different bands, it may be necessary to use such new or reconfigured coupling devices to achieve the desired operating parameters. This may require separate designs for systems operating at different frequency bands, which may increase system complexity, design effort, and cost. Alternatively, the system may also be completely limited to certain bandwidths.

[0013] A system utilizing an overcoupling technique for a directional coupler is disclosed herein, which allows the system to generate orthogonal signals for data processing over a wider fractional bandwidth. The dimensions of the coupled conductive strips can be selected at a quarter wavelength of a center frequency within a desired bandwidth so that overcoupling occurs between an input port and a coupled port of a directional coupler formed using conductive strips placed in different metal layers. Advantageously, the disclosed system and circuits thereof can achieve improved performance relative to a fractional bandwidth (e.g., approximately 30% of the center frequency) while reducing the need for additional design, design resources, and costs to operate at different but adjacent frequency bands, among other situations.

[0014] In an example embodiment, a system is provided. The system includes a first amplifier, a first mixer, a second mixer, a local oscillator, an orthogonal signal generation subcircuit, a second amplifier, a third amplifier, a first analog-to-digital converter (ADC), and a second ADC. The first amplifier is configured to be coupled to an antenna. The first and second mixers are coupled to the first amplifier. The orthogonal signal generation subcircuit is coupled to the first mixer, the second mixer, and the local oscillator. The second amplifier is coupled to the first mixer, and the third amplifier is coupled to the second mixer. The first ADC is coupled to the second amplifier, and the second ADC is coupled to the third amplifier. The orthogonal signal generation subcircuit includes: a first conductive strip having a first width and a first length, arranged in a first layer of an interconnect of a substrate; and a second conductive strip having a second width and a second length, arranged in a second layer of the interconnect. The first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect, so that the first conductive strip and the second conductive strip form a directional coupler. The first conductive strip includes: a first end, which is configured to be coupled to a local oscillator; and a second end, which is opposite to the first end. The second conductive strip includes: a third end configured to be coupled to the first hybrid and electromagnetically coupled to the first end; and a fourth end opposite to the third end. The first length of the first conductive strip and the second length of the second conductive strip are based on a quarter wavelength of a center frequency of a bandwidth of the directional coupler. In addition, the first width of the first conductive strip and the second width of the second conductive strip are configured to generate a coupling gain between the first end and the third end of the directional coupler. The coupling gain between the first end of the first conductive strip and the first end of the second strip may be greater than the throughput gain between the first end and the second end of the first conductive strip.

[0015] In another example embodiment, a device is provided. The device includes: a first conductive strip having a first width and a first length, arranged in a first layer of an interconnect of a substrate; and a second conductive strip having a second width and a second length, arranged in a second layer of the interconnect. The first conductive strip and the second conductive strip are arranged in parallel relative to each other in respective layers of the interconnect, so that the first conductive strip and the second conductive strip form a directional coupler. The first conductive strip includes: a first end, configured to be coupled to a local oscillator; and a second end, which is opposite to the first end. The second conductive strip includes: a third end, configured to be coupled to a first mixer and electromagnetically coupled to the first end; and a fourth end, which is opposite to the third end. The first length of the first conductive strip and the second length of the second conductive strip are a quarter wavelength based on a center frequency of a bandwidth of the directional coupler. In addition, the first width of the first conductive strip and the second width of the second conductive strip are configured to generate a coupling gain between the first end and the third end of the directional coupler. The coupling gain between the first end of the first conductive strip and the first end of the second strip may be greater than the throughput gain between the first end and the second end of the first conductive strip.

[0016] In yet another example embodiment, a device is provided. The device includes: a first conductive strip having a first width and a first length, arranged in a first layer of an interconnect of a substrate; a second conductive strip having a second width and a second length, arranged in a second layer of the interconnect; a third conductive strip having a third width and a third length, arranged in the first layer of the interconnect; and a fourth conductive strip having a fourth width and a fourth length, arranged in the second layer of the interconnect. The first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect, such that the first conductive strip and the second conductive strip form a directional coupler. The third conductive strip and the fourth conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect, such that the third conductive strip and the fourth conductive strip form a second directional coupler. The first conductive strip includes: a first end, configured to be coupled to a local oscillator; and a second end, which is opposite to the first end. The second conductive strip includes: a third end, configured to be coupled to a first mixer and electromagnetically coupled to the first end; and a fourth end, which is opposite to the third end. The third conductive strip includes: a fifth end configured to be coupled to a local oscillator; and a sixth end opposite to the fifth end. The fourth conductive strip includes: a seventh end configured to be coupled to the second mixer and electromagnetically coupled to the fifth end; and an eighth end opposite to the seventh end, coupled to the resistor. The first length, the second length, the third length, and the fourth length are a quarter wavelength of the center frequency based on the bandwidth of the first and second directional couplers. The first width and the second width are configured to generate a first coupling gain between the first end and the third end of the first directional coupler. The first coupling gain between the first end of the first strip and the third end of the second strip is greater than the first throughput gain between the first end and the second end of the first conductive strip. The third width and the fourth width are configured to generate a second coupling gain between the fifth end and the seventh end of the second directional coupler, wherein the second coupling gain between the fifth end of the third strip and the seventh end of the fourth strip is greater than the second throughput gain between the fifth end and the sixth end of the third conductive strip.

[0017] Figure 1 An example operating environment for quadrature signal generation that may be used in accordance with an embodiment is described. Figure 1An operating environment 100 is included, which includes an antenna 105, a low noise amplifier (LNA) 110, a mixer 115 (e.g., an in-phase mixer), a mixer 116 (e.g., a quadrature mixer), a bandpass filter 117, a bandpass filter 118, a local oscillator (LO) 120, a quadrature signal generation subcircuit 125, an intermediate frequency (IF) amplifier 130, an IF amplifier 131, an analog-to-digital converter (ADC) 135, an ADC 136, a digital signal processor (DSP) 145, and a DSP 146. In various examples, the quadrature signal generation subcircuit 125 is configured to generate two output signals, providing a first output signal to the mixer 115 and a second output signal to the mixer 116, which can undergo further processing to generate outputs 140 and 141, respectively.

[0018] The system shown in operating environment 100 represents one or more on-chip integrated circuits (e.g., system on chip (SoC)) via, for example, CMOS manufacturing processes, which are capable of processing signals received by antenna 105 for downstream use. The integrated chip may employ one or more types of conductive traces, strips, solder types, dielectric materials, and other components to perform signal reception and processing functions. For example, the system may be used to receive and process radar data from antenna 105. However, other uses are contemplated. In some embodiments, the system may include more than about Figure 1 The components shown may be greater or less than the components shown.

[0019] Antenna 105 is included and represents an antenna capable of receiving signals over the air and converting the signals into an electrical current. Antenna 105 can operate in various bandwidths and radio frequencies, such as in narrowband or wideband. Antenna 105 can be coupled to provide a received signal to LNA 110.

[0020] LNA 110 represents a low noise amplifier, which includes various electronic components (e.g., inductors, transistors, etc.) capable of amplifying a signal received via antenna 105 while minimizing degradation of the signal-to-noise ratio of the signal and matching the impedance of the signal to improve power transfer over various frequency bands. LNA 110 may be coupled or connected to provide an amplified signal to both mixer 115 and mixer 116.

[0021] Mixers 115 and 116 represent electronic mixers that may include one or more electronic components capable of combining two or more signals, such as an amplified signal from LNA 110 and a signal from quadrature signal generation subcircuit 125, in operating environment 100 to generate a down-converted signal. More specifically, mixer 115 may be coupled to receive an amplified signal from LNA 110 and a signal from quadrature signal generation subcircuit 125, and coupled to provide a first down-converted signal to bandpass filter 117. Mixer 116 may be coupled to receive an amplified signal from LNA 110 and a signal from quadrature signal generation subcircuit 125, and coupled to provide a second down-converted signal to bandpass filter 118. Bandpass filters 117 and 118 may filter the signals provided by mixers 115 and 116, respectively, and output the filtered signals to IF amplifier 130 and IF amplifier 131, respectively. In various examples, mixers 115 and 116 may operate as downconverters, however, in other examples, mixers 115 and 116 may alternatively or additionally operate as upconverters.

[0022] The quadrature signal generation subcircuit 125 represents a quadrature signal generator capable of generating a signal having both an in-phase and a quadrature portion based on a signal provided by the local oscillator 120. In various examples, the quadrature signal generation subcircuit 125 generates one or more signals having a first phase and one or more different signals having a second phase. The first phase and the second phase may be 90 degrees out of phase with respect to each other. For example, the first phase may be 0 degrees and the second phase may be 90 degrees. However, any other combination or variation may be envisioned. The signals generated by the quadrature signal generation subcircuit 125 may also have different polarities with respect to each other. For example, the quadrature signal generation subcircuit 125 may generate a first signal having a first phase (which is a positive phase signal), a second signal having a first phase (which is a negative phase signal), a third signal having a second phase (which is a positive phase signal), and a fourth signal having a second phase (which is a negative phase signal).

[0023] In order to generate such differential orthogonal signals, the orthogonal signal generation subcircuit 125 may include one or more directional couplers, which are formed using conductive strips on a layer of interconnects of a substrate (e.g., a silicon substrate) during a CMOS manufacturing process. The orthogonal signal generation subcircuit 125 may include two conductive strips located on a first layer of the substrate and two conductive strips located on a second layer of the substrate. The conductive strips of the first layer and the second layer may be positioned within the respective layers so that the conductive strips form two different directional couplers. In various instances, the conductive strips may include microstrip lines, embedded microstrip lines, or embedded strip lines (striplines), however, other types of conductive strips or traces may be used. The conductive strips may be rectangular or any other type of shape. In an example, the first and second layers may be metal layers formed on the substrate, and during the CMOS process, the conductive strips may be stacked or otherwise arranged on the metal layer.

[0024] The first directional coupler may include a first strip and a second strip, wherein the first strip is located in a first layer of a metal interconnect deposited on a substrate, and the second strip is located in a second layer of the interconnect of the substrate. The first layer and the second layer may be different layers within the interconnect, such as a top layer and a layer directly below the top layer, respectively. The first strip and the second strip may be arranged within the respective layers such that the first strip is positioned directly above the second strip and parallel to the second strip. Similarly, the second directional coupler may include a third strip located in the first layer of the interconnect and a fourth strip located in the second layer of the interconnect, and the third and fourth strips may also be arranged parallel to each other. The first and third strips of the first layer may be positioned a distance apart from each other, and the second and fourth strips of the second layer may be positioned a distance apart from each other. An illustration of this positioning of the conductive strips is provided in Figure 2C and described below.

[0025] Each of the conductive strips includes two ends that can be coupled to or connected to other components in the operating environment 100. The first end can be located on the proximal side of the corresponding strip, and the second end can be located on the distal side of the corresponding strip. With reference to the first directional coupler, the first end of the first conductive strip can be referred to as the input port of the first directional coupler, the second end of the first conductive strip can be referred to as the through port of the directional coupler, the first end of the third conductive strip can be referred to as the coupling port of the first directional coupler, and the second end of the third conductive strip can be referred to as the isolation port of the first directional coupler. With reference to the second directional coupler, the first end of the second conductive strip can be referred to as the input port of the second directional coupler, the second end of the second conductive strip can be referred to as the through port of the second directional coupler, the first end of the fourth conductive strip can be referred to as the coupling port of the second directional coupler, and the second end of the fourth conductive strip can be referred to as the isolation port of the second directional coupler. For each directional coupler, the input port and the coupling port of the conductive strip can be aligned with each other in the same vertical plane in the corresponding layer of the interconnect, and the through port and the isolation port can be aligned with each other in the same vertical plane in the corresponding layer of the interconnect. Additionally, the input port and the coupled port of the directional coupler may be electromagnetically coupled together.

[0026] In various examples, the input port of the directional coupler, or the first end of the first conductive strip and the second conductive strip, can be coupled to a local oscillator 120. The local oscillator 120 represents a timing circuit having an oscillator capable of generating a differential clock signal. The local oscillator 120 can be coupled or connected to provide a positive input signal (e.g., a local oscillator signal and / or a clock signal) to the input port of the first directional coupler, and to provide a negative input signal having substantially the same amplitude, phase, and frequency as the positive input signal to the input port of the second directional coupler. When the local oscillator 120 supplies an input signal to the directional coupler, the signal can travel electrically through the top conductive strip (e.g., the first conductive strip, the second conductive strip) and electromagnetically from the top conductive strip to the bottom conductive strip (e.g., the third conductive strip, the fourth conductive strip). In various examples, based on factors such as the size of the conductive strip, the coupling coefficient of the conductive strip, and the proximity of the conductive strips within a given directional coupler, at the center frequency, the gain of the signal at the coupled port of the directional coupler can be higher than the gain at the penetration port of the directional coupler (i.e., over-coupling). Specifically, in some examples, the coupling factor at the coupled port of the directional coupler can be approximately 2.7 dB, where for equal power distribution between the coupled port and the through port, the coupling factor is 3 dB. For example, where the directional coupler design is intended to accommodate multiple local oscillator frequencies, the center frequency can be selected to be between the various frequencies (e.g., about 67.5 GHz for a directional coupler suitable for 60 GHz and 80 GHz local oscillator applications).

[0027] In addition, the phase of the signal may be different after passing through the directional coupler. For example, the signal at the through port of the first directional coupler may be a positive phase signal with a phase of 90 degrees, the signal at the through port of the second directional coupler may be a negative phase signal with a phase of 90 degrees and therefore 270 degrees, the signal at the coupled port of the first directional coupler may be a positive phase signal with a phase of 0 degrees, and the signal at the coupled port of the second directional coupler may be a negative phase signal with a phase of 0 degrees and therefore 180 degrees. Thus, the directional coupler may generate a signal having a gain and a bandwidth and phase different from the input signal provided by the local oscillator 120.

[0028] Hybrids 115 and 116 may be coupled to or connected to the ends of the directional coupler to receive signals generated by the directional coupler. For example, hybrid 115 may be coupled at the through port of the directional coupler to receive a differential 90 degree signal, and hybrid 116 may be coupled at the coupled port of the directional coupler to receive a differential 0 degree signal. More specifically, hybrids 115 and 116 may be connected to traces on the interconnect to receive signals from the ends of the conductive strips.

[0029] The size (length, width, height) of the conductive strips, the proximity between the first and third conductive strips (i.e., the first directional coupler), and the proximity between the second and fourth conductive strips (i.e., the second directional coupler) can be selectively selected based on the desired performance of the directional coupler. For example, in operation, the directional coupler can generate differential orthogonal signals over a certain desired bandwidth when coupled to receive signals from the local oscillator 120. Therefore, the size and proximity may affect the bandwidth and / or gain of the directional coupler. Advantageously, based on the overcoupling of the conductive strips of each directional coupler, a wide bandwidth can be achieved by the differential orthogonal signal generation subcircuit 125 (e.g., 50 to 85 GHz).

[0030] Mixers 115 and 116 may multiply the signal received from LNA 110 with the signal received from quadrature signal generation subcircuit 125 and provide down-converted signals to IF amplifiers 130 and 131, respectively. IF amplifiers 130 and 131 are configured to further amplify the mixed signals in the receiver channel. IF amplifier 130 may be coupled or connected to provide a signal to ADC 135, and IF amplifier 131 may be coupled or connected to provide a signal to ADC 136.

[0031] ADCs 135 and 136 are included to convert the down-converted and amplified analog signals into digital signals. ADC 135 may convert the corresponding signals to generate output 140. ADC 136 may convert the corresponding signals and generate output 141. Outputs 140 and 141 may represent digital signals received by antenna 105 after conversion, amplification, modulation, and other processing. In various examples, ADCs 135 and 136 may provide outputs 140 and 141, respectively, to a digital signal processing (DSP) engine or another downstream processing module (e.g., digital signal processors 145 and 146).

[0032] Figure 2A , 2B 2C illustrate aspects of conductive features used in a quadrature signal generation subcircuit according to an embodiment. Figure 2A Aspect 201 is included showing a top view of a first layer 210 of metal layers of an interconnect deposited onto a substrate and components arranged on the interconnect layer 210. Layer 210 includes conductive features in the form of strips 215 and 220, nodes 218, 219, 223, and 224, and ground planes 225 and 226. The conductive features of layer 210 are disposed within an interlayer dielectric (ILD), which is omitted to better illustrate the conductive features. Figure 2B Aspect 202 is included showing a top view of a second layer 211 of interconnect and components disposed on the interconnect layer 211. Layer 211 includes conductive features in the form of strips 230 and 235, nodes 233, 234, 238, and 239, resistor 240, and ground planes 245 and 246. The conductive features of layer 211 are disposed within an ILD, which is omitted to better illustrate the conductive features. Figure 2C Included is aspect 203, which shows a three-dimensional isometric view of layers 210 and 211 of circuit board 205. In various examples, components of the circuit board can be configured to perform an orthogonal signal generation process.

[0033] First reference Figure 2A Aspect 201 of the present invention shows a substrate having an interconnect layer 210 on which an orthogonal signal generator (eg, Figure 1 201 ) is a view of components of the orthogonal signal generation subcircuit 125, such as metal layers deposited onto a substrate during a CMOS process. In various examples, layer 210 can be a top layer of the substrate. In other examples, layer 210 can be a layer other than a top layer of interconnects. The components shown in aspect 201 can be embedded or otherwise attached to layer 210.

[0034] Strips 215 and 220 are included on layer 210 and represent conductive strips (e.g., coupled strips) that form part of two different directional couplers. In various examples, strips 215 and 220 can be made of conductive metal having lengths 216 and 221, respectively, widths 217 and 222, respectively, and depths that depend on the CMOS process. In one example, the shapes of strips 215 and 220 are rectangular, however, other shapes including tapered shapes can be used. Each of strips 215 and 220 includes two ends that can be used as inputs or outputs of an orthogonal signal generator. The first end of strip 215 can be coupled to node 218, and the second end of strip 215 can be coupled to node 219. The first end of strip 220 can be coupled to node 223, and the second end of strip 220 can be coupled to node 224. Nodes 218, 219, 223, and 224 may represent ports, pins, or pads that may respectively couple or connect (i.e., physically) a component to an interconnect of strips 215 and 220. The first ends of strips 215 and 220 may be referred to as input ports, while the second ends of strips 215 and 220 may be referred to as pass-through ports.

[0035] In various examples, the input ports of strips 215 and 220 can be coupled or connected to local oscillators (eg, Figure 1 The local oscillator may supply a differential local oscillator signal by providing a positive local oscillator signal to stripe 215 via node 218 and providing a negative local oscillator signal having substantially the same amplitude, phase, and frequency as the positive local oscillator signal to stripe 220 via node 223. The pass-through ports of stripes 215 and 220 may be coupled or connected to a mixer (e.g., Figure 1 When a signal is supplied to strips 215 and 220, the signal may travel from a first end to a second end of strips 215 and 220, reaching the mixer via nodes 219 and 224. The signal received by the mixer is relative to the signal received by the second mixer (e.g., Figure 1 The signal received by the mixer 116 may have a phase of 90 degrees. However, signals of other phases may be used.

[0036] Layer 210 further includes ground planes 225 and 226. Ground planes 225 and 226 may have widths 227 and 228, respectively. Ground planes 225 and 226 may be connected to layers 210 and 226 in the substrate via vias. Figure 2B The vias may allow elements of layer 210 (eg, ground planes 225 and 226) to connect to elements of other layers of the interconnect.

[0037] The dimensions of the strips 215 and 220, the ground planes 227 and 228, the total width 253 of the strips 215, the strips 220, the ground planes 227 and the ground planes 228, and the width of the gaps between each of these elements, such as the gap 250 between the strips 215 and 220, the gap 251 between the strips 215 and the ground plane 225, and the gap 252 between the strips 220 and the ground plane 226, can be configured to generate desired conductivity and coupling gain performance. For example, such dimensions may affect the gain and phase of a signal traveling from a first end of the strip to a second end of the strip. In addition, such dimensions may further affect the relationship between the strips 215 and 220 of the layer 210 and the next mentioned Figure 2B 215 and 220. In one example, the lengths 216 and 221 of the strips 215 and 220, respectively, can each be 450 μm. In addition, the total width 253 of the elements on the interconnect can be 80 μm. When the strip forms a directional coupler with the strip below it, the total width 253 can allow the strip to have a characteristic impedance of approximately 100 ohms. Importantly, this can provide impedance matching while also generating over-coupling gain when the signal is transmitted through the strips 215 and 220. In other examples, other dimensions are contemplated.

[0038] Reference now Figure 2B , aspect 202 shows layer 211 of the interconnect, which may represent a layer below layer 210 within the interconnect. In various examples, layer 211 is a layer directly below layer 210. More specifically, in an interconnect having 9 layers deposited onto a substrate, layer 210 may be the top layer or layer 9, and layer 211 may be layer 8. There may further be dielectric layers between each of the layers, including between layers 210 and 211.

[0039] Layer 211 includes strips 230 and 235, which are included as other parts of two different directional couplers. Strips 230 and 235 may also include conductive strips of rectangular shape, and may be positioned in the same manner as strips 215 and 220 of layer 210, directly below and parallel to strips 215 and 220, respectively. Thus, in use, in the interconnect, strips 215 and 230 form a first directional coupler, and strips 220 and 235 form a second directional coupler.

[0040] In various examples, strips 230 and 235 may be made of conductive metal having lengths 231 and 236, respectively, widths 232 and 237, respectively, and depths, which may depend on the CMOS process. Each of strips 230 and 235 includes two ends that may be used as outputs of a quadrature signal generator. A first end of strip 230 may be coupled to node 233, and a second end of strip 230 may be coupled to node 234. A first end of strip 235 may be coupled to node 238, and a second end of strip 235 may be coupled to node 239. Nodes 233, 234, 238, and 239 may represent ports, pins, or pads that may couple or connect components to strips 230 and 235, respectively, depending on the CMOS process. For example, resistor 240 may be coupled to or connected to strips 230 and 235 via nodes 234 and 239. The first ends of the strips 230 and 235 may be referred to as coupled ports, while the second ends of the strips 230 and 235 may be referred to as isolated ports.

[0041] In various examples, the coupled ports of strips 230 and 235 can be electromagnetically coupled to the input ports of strips 215 and 220, respectively, through layers 210 and 211 of the interconnect. The coupled ports can be coupled or connected to different mixers (e.g., Figure 1 The mixer 116 of strips 215 and 220 is provided. When the local oscillator supplies a differential signal to the input port of strips 215 and 220, a coupling factor is generated between the input port and the coupling port. In various instances, the coupling factor between the input port and the coupling port can generate a coupling gain greater than the throughput gain between the input port and the penetration port. This can be referred to as over-coupling because more power is delivered to the coupling port than to the penetration port. The second mixer can receive a positive phase signal from strip 230 via node 233 and receive a negative phase signal from strip 235 via node 238. The signal received by the second mixer can have a phase that is 90 degrees out of phase with respect to the signal received by the mixer from strips 215 and 220, respectively, via nodes 219 and 224. For example, the signal received by the second mixer can have a phase of 0 degrees or some other degree that is 90 degrees different from another phase of the signal received by the first mixer.

[0042] Layer 211 further includes ground planes 245 and 246. Ground planes 245 and 246 may have widths 247 and 248. Ground planes 245 and 246 may connect through vias to other metal layers below layer 211 of the interconnect. For example, ground planes 245 and 246 may connect to ground planes 225 and 226 of layer 210, respectively, and other components of layer 210.

[0043] The dimensions of the strips 230 and 235, the ground planes 245 and 246, the total width 257 of the strips 230, the strips 235, the ground planes 245 and the ground planes 246, and the gap widths between each of these elements, such as the gap 254 between the strips 230 and 235, the gap 255 between the strips 230 and the ground plane 245, and the gap 256 between the strips 235 and the ground plane 246, can be configured to generate the desired conductivity and coupling gain performance. For example, such dimensions may affect the gain and phase of a signal traveling from a first end of the strip to a second end of the strip. In addition, such dimensions can further affect the coupling gain between the strips 215 and 220 of the layer 210 and the strips 230 and 235. In an example, the lengths 231 and 236 of the strips 230 and 235, respectively, can each be 450 μm. In addition, the total width 257 of the elements on the interconnect can be 80 μm. The total width 257 can allow the strip to have a characteristic impedance of approximately 100 ohms when the strip forms a directional coupler with the strip below it. Importantly, this can provide impedance matching while also generating over-coupling gain when signals are transmitted through strips 230 and 235. In other examples, other dimensions are contemplated.

[0044] Next reference Figure 2C , Figure 2C Aspect 203 is included, which shows a 3D model of layers 210 and 211 of interconnect 205 and its components, the interconnect representing a CMOS process interconnect. As illustrated, layer 210 can be the top layer of interconnect 205, and layer 211 can be the layer directly below layer 210 in interconnect 205. Therefore, the components of layer 210 can be positioned above and parallel to the components of layer 211. More specifically, strips 215 and 220 can be positioned above and parallel to strips 230 and 235, respectively, and ground planes 225 and 226 can be positioned above and parallel to ground planes 245 and 246, respectively. As mentioned, the size of strips 215, 220, 230, and 235 can affect the coupling factor, and therefore the coupling gain and throughput gain of the directional coupler. In addition, the proximity between strips 215 and 230 and strips 220 and 235 can further affect the performance of the directional coupler.

[0045] ILD layer 250 may be included between layers 210 and 211. ILD layer 251 may be included on top of layer 210. Additional dielectric material layers may also be included between other layers of interconnect 205. ILD layers 250 and 251 include dielectric materials formed using various materials used in standard silicon processes (e.g., CMOS, SiGe BiCMOS, etc.). The type of ILD layer 250 and its thickness may be defined by each silicon process.

[0046] Various signal vias may be included in the interconnect 205 between layer 210, layer 211, ILD layer 250 and ILD layer 251, and other layers of the interconnect 205. The signal vias may span from the outside and / or the inside from layer to layer. For example, the signal vias may provide a connection from node 218 and thus to stripe 215, from another layer of the interconnect 205, or to a component external to the interconnect.

[0047] Different material compositions, sizes (e.g., thickness, length, width), arrangements, and shapes of signal vias, conductive strips, ground planes, dielectric materials, etc. may also be selected to alter or adapt desired operating characteristics of the differential orthogonal signal generation subcircuit and receiver channel as a whole, such as operating gain, bandwidth, and impedance.

[0048] Although some of the examples provided herein are described in the context of a signal receiver or orthogonal signal generating system, circuit, subcircuit, component, element, architecture, or environment, the systems, circuits, and methods described herein are not limited to such embodiments and may be applied to various other processes, systems, applications, devices, and the like.

[0049] Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprise", "comprising", etc. should be interpreted in an inclusive sense, rather than in an exclusive or exhaustive sense, that is, in the sense of "including but not limited to". As used herein, the terms "connect", "couple" or any variation thereof mean any direct or indirect connection or coupling between two or more elements; the coupling or connection between elements may be physical, logical, or a combination thereof. In addition, when used in this application, the words "herein", "above", "below" and words of similar meaning refer to the application as a whole, not to any particular part of the application. Where the context permits, words used in the singular or plural in the above specific embodiments may also include the plural or singular, respectively. The word "or" with respect to a list of two or more items covers all of the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list.

[0050] The phrases "in some embodiments," "according to some embodiments," "in the illustrated embodiments," "in other embodiments," etc. generally mean that the particular feature, structure, or characteristic following the phrase is included in at least one embodiment of the present technology, and may be included in more than one embodiment. Additionally, such phrases do not necessarily refer to the same embodiment or different embodiments.

[0051] The above-mentioned specific implementation of the example of technology is not intended to be exhaustive or to limit technology to the exact form disclosed above. Although the specific example of technology is described above for illustrative purposes, as will be appreciated by those skilled in the relevant art, various equivalent modifications can be made within the scope of technology. For example, although the process or element is presented in a given order, alternative embodiments can perform routines with steps in different orders, or adopt a system with elements or components, and some processes or elements can be deleted, moved, added, subdivided, combined and / or modified to provide alternatives or sub-combinations. Each of these processes or elements can be implemented in various different ways. In addition, any specific numbers mentioned herein are only examples; alternative embodiments can adopt different values ​​or ranges.

[0052] The teaching of the technology provided herein can be applied to other systems, not necessarily the system described above. The elements and actions of the various examples described above can be combined to provide other embodiments of the technology. Some alternative embodiments of the technology can not only include the extra elements of those embodiments mentioned above, but also include fewer elements.

[0053] In view of the above-mentioned specific embodiments, these and other changes can be made to the technology. Although the above description describes certain examples of the technology and describes the best mode envisioned, no matter how detailed the above content appears in this article, the technology can be practiced in many ways. The details of the system can change significantly in its specific embodiment while still being covered by the technology disclosed herein. As mentioned above, the specific terms used when describing certain features or aspects of the technology should not be understood to imply that the terms are redefined herein as any specific characteristics, features or aspects of the technology associated with the terms. In general, unless such terms are clearly defined in the above-mentioned specific embodiments, the terms used in the attached claims should not be interpreted as limiting the technology to the specific examples disclosed in the specification. Therefore, the actual scope of the technology not only covers the disclosed examples, but also covers all equivalent ways of practicing or implementing the technology in the claims.

[0054] In order to reduce the number of claims, certain aspects of the technology are presented below in the form of certain claims, but applicants contemplate various aspects of the technology in any number of claim forms. For example, although only one aspect of the technology is described as a computer-readable media claim, other aspects may also be embodied as a computer-readable media claim, or in other forms, such as a device-plus-function claim. Any claim intended to be processed under 35 U.S.C. §112(f) will begin with the words "means for," but the use of the term "for" in any other context is not intended to invoke processing under 35 U.S.C. §112(f). Therefore, applicants reserve the right to seek additional claims after filing this application to seek such additional claim forms in this application or a continuation application.

Claims

1. A system comprising: a first amplifier configured to be coupled to an antenna; a first mixer and a second mixer coupled to the first amplifier; Local oscillator; a quadrature signal generation subcircuit coupled to the first mixer, the second mixer, and the local oscillator; a second amplifier coupled to the first mixer; a third amplifier coupled to the second mixer; a first analog-to-digital converter ADC coupled to the first IF amplifier; and a second ADC coupled to the second IF amplifier; The orthogonal signal generating subcircuit comprises: a first conductive strip having a first width and a first length disposed in a first layer of interconnects of the substrate; and a second conductive strip having a second width and a second length disposed in a second layer of the interconnect; wherein the first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the first conductive strip and the second conductive strip form a directional coupler; wherein the first conductive strip comprises: a first end configured to be coupled to the local oscillator; and a second end opposite to the first end; wherein the second conductive strip comprises: a third end configured to be coupled to the first mixer and electromagnetically coupled to the first end; and a fourth end opposite to the third end; wherein the first length of the first conductive strip and the second length of the second conductive strip are based on a quarter wavelength of a center frequency of a bandwidth of the directional coupler; and The first width of the first conductive strip and the second width of the second conductive strip are selectively selected based on a coupling gain between the first end and the third end of the directional coupler, wherein the coupling gain is expected to be greater than a throughput gain between the first end and the second end of the first conductive strip.

2. The system of claim 1, wherein the quadrature signal generation subcircuit further comprises: a third conductive strip having a third width and a third length disposed in the first layer of the interconnect; and a fourth conductive strip having a fourth width and a fourth length disposed in the second layer of the interconnect; wherein the third conductive strip and the fourth conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the third conductive strip and the fourth conductive strip form a second directional coupler; wherein the third conductive strip comprises: a fifth end configured to be coupled to the local oscillator; and a sixth end opposite to the fifth end; wherein the fourth conductive strip comprises: a seventh end configured to be coupled to the second mixer and electromagnetically coupled to the fifth end; and an eighth end opposite the seventh end; wherein the third length of the third conductive strip and the fourth length of the fourth conductive strip are based on the quarter wavelength of the center frequency of the bandwidth; and wherein the third width of the third conductive strip and the fourth width of the fourth conductive strip are configured to generate an additional coupling gain between the fifth end and the seventh end of the second directional coupler, wherein the additional coupling gain is greater than an additional throughput gain between the fifth end and the sixth end of the third conductive strip.

3. The system of claim 2, wherein the quadrature signal generation subcircuit further comprises a resistor coupled to the fourth end of the second conductive strip and to the eighth end of the fourth conductive strip.

4. The system of claim 2, wherein the directional coupler is configured to generate a first signal based on the local oscillator providing a positive phase signal to the first end of the first conductive strip, and provide the first signal to the first mixer via the third end of the second conductive strip.

5. The system of claim 4, wherein the second directional coupler is configured to generate a second signal based on the local oscillator providing a negative phase signal to the fifth end of the third conductive strip, and provide the second signal to the second mixer via the seventh end of the fourth conductive strip.

6. The system of claim 5, wherein the first signal has a first phase, wherein the second signal has a second phase, and wherein the first signal and the second signal are 90 degrees out of phase with respect to each other.

7. The system of claim 2, wherein the bandwidth is approximately between 50 and 85 GHz, and wherein the center frequency of the quarter wavelength of the bandwidth is approximately 67.5 GHz.

8. The system of claim 7 , wherein the coupling gain and the further coupling gain are approximately 2.7 dB, and wherein the first coupling coefficient of the directional coupler and the second coupling coefficient of the second directional coupler are selectively selected so that the coupling gain and the further coupling gain occur at the center frequency of the quarter wavelength within the desired bandwidth.

9. The system of claim 2, wherein the quadrature signal generation subcircuit further comprises: one or more ground planes disposed on the first layer of the interconnect; one or more additional ground planes disposed on the second layer of the interconnect; a fifth conductive strip disposed on the third layer of the interconnect; and one or more through-holes located between the first layer, the second layer, and the third layer of the interconnect, wherein the one or more ground planes and the one or more additional ground planes are coupled to the fifth conductive strip through the one or more through-holes.

10. An apparatus comprising: a first conductive strip having a first width and a first length disposed in a first layer of interconnects of the substrate; and a second conductive strip having a second width and a second length disposed in a second layer of the interconnect; wherein the first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the first conductive strip and the second conductive strip form a directional coupler; wherein the first conductive strip includes a first end configured to be coupled to a local oscillator and includes a second end opposite the first end; wherein the second conductive strip includes a third end configured to be coupled to the mixer and electromagnetically coupled to the first end, and includes a fourth end opposite the third end; wherein the first length of the first conductive strip and the second length of the second conductive strip are selectively selected based on a quarter wavelength of a bandwidth of the directional coupler; and The first width of the first conductive strip and the second width of the second conductive strip are configured to generate a coupling gain between the first end and the third end of the directional coupler, wherein the coupling gain is greater than a throughput gain between the first end and the second end of the first conductive strip.

11. The device according to claim 10, further comprising: a third conductive strip having a third width and a third length disposed in the first layer of the interconnect; and a fourth conductive strip having a fourth width and a fourth length disposed in the second layer of the interconnect; wherein the third conductive strip and the fourth conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the third conductive strip and the fourth conductive strip form a second directional coupler; wherein the third conductive strip comprises: a fifth end configured to be coupled to the local oscillator; and a sixth end opposite to the fifth end; wherein the fourth conductive strip comprises: a seventh end configured to be coupled to the second mixer and electromagnetically coupled to the fifth end; and an eighth end opposite to the seventh end; wherein the third length of the third conductive strip and the fourth length of the fourth conductive strip are based on the quarter wavelength of the bandwidth; and wherein the third width of the third conductive strip and the fourth width of the fourth conductive strip are configured to generate an additional coupling gain between the fifth end and the seventh end of the second directional coupler, wherein the additional coupling gain is greater than an additional throughput gain between the fifth end and the sixth end of the third conductive strip.

12. The device of claim 11, further comprising a resistor coupled to the fourth end of the second conductive strip and to the eighth end of the fourth conductive strip.

13. The device of claim 11, wherein the directional coupler is configured to generate a first signal based on the local oscillator providing a positive phase signal to the first end of the first conductive strip, and provide the first signal to the first mixer via the third end of the second conductive strip.

14. The device of claim 13, wherein the second directional coupler is configured to generate a second signal based on the local oscillator providing a negative phase signal to the fifth end of the third conductive strip, and provide the second signal to the second mixer via the seventh end of the fourth conductive strip.

15. The device of claim 14, wherein the first signal has a first phase, wherein the second signal has a second phase, and wherein the first signal and the second signal are 90 degrees out of phase with respect to each other.

16. The device of claim 11, wherein the bandwidth is approximately between 50 and 85 GHz, and wherein a center frequency of the quarter wavelength of the bandwidth is approximately 67.5 GHz.

17. The apparatus of claim 16, wherein the coupling gain and the further coupling gain are approximately 2.7 dB, and wherein the first coupling coefficient of the directional coupler and the second coupling coefficient of the second directional coupler are configured such that the coupling gain and the further coupling gain occur at a quarter wavelength frequency of the bandwidth.

18. An apparatus comprising: a first conductive strip having a first width and a first length disposed in a first layer of interconnects of the substrate; a second conductive strip having a second width and a second length disposed in a second layer of the interconnect; a third conductive strip having a third width and a third length disposed in the first layer of the interconnect; and a fourth conductive strip having a fourth width and a fourth length disposed in the second layer of the interconnect; wherein the first conductive strip and the second conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the first conductive strip and the second conductive strip form a first directional coupler; wherein the third conductive strip and the fourth conductive strip are arranged in parallel with respect to each other in respective layers of the interconnect such that the third conductive strip and the fourth conductive strip form a second directional coupler; wherein the first conductive strip includes a first end configured to be coupled to a local oscillator and includes a second end opposite the first end; wherein the second conductive strip includes a third end configured to be coupled to a mixer and electromagnetically coupled to the first end, and includes a fourth end opposite the third end, the fourth end being coupled to a resistor; wherein the third conductive strip comprises: a fifth end configured to be coupled to the local oscillator; and a sixth end, which is opposite to the fifth end; wherein the fourth conductive strip comprises: a seventh end configured to be coupled to the second mixer and electromagnetically coupled to the fifth end; and an eighth terminal, opposite to the seventh terminal, coupled to the resistor; wherein the first length, the second length, the third length, and the fourth length are based on a quarter wavelength of a center frequency in a bandwidth of the first directional coupler and the second directional coupler; wherein the first width and the second width are configured to generate a first coupling gain between the first end and the third end of the first directional coupler, the first coupling gain being greater than a first throughput gain between the first end and the second end of the first conductive strip; and The third width and the fourth width are configured to generate a second coupling gain between the fifth end and the seventh end of the second directional coupler, the second coupling gain being greater than a second throughput gain between the fifth end and the sixth end of the third conductive strip.

19. The device according to claim 18, wherein: The first directional coupler is configured to generate a first signal based on the local oscillator providing a positive phase signal to the first end of the first conductive strip, and provide the first signal to the first mixer via the third end of the second conductive strip; The second directional coupler is configured to generate a second signal based on the local oscillator providing a negative phase signal to the fifth end of the third conductive strip, and provide the second signal to the second mixer via the seventh end of the fourth conductive strip; The first signal has a first phase; The second signal has a second phase; and The first signal and the second signal are 90 degrees out of phase with respect to each other.

20. The apparatus of claim 18, wherein the bandwidth is approximately between 50 and 85 GHz, wherein the quarter wavelength of the bandwidth is approximately 67.5 GHz, wherein the coupling gain and the further coupling gain are approximately 2.7 dB, and wherein the first coupling coefficient of the first directional coupler and the second coupling coefficient of the second directional coupler are configured such that the coupling gain and the further coupling gain occur at a frequency of one quarter wavelength of the bandwidth.

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