Terahertz on-chip power synthesis structure based on slot line

Abstract

The invention discloses a slot line-based terahertz on-chip power synthesis structure, which comprises a differential on-chip microstrip line-slot line switching structure (1) and an on-chip Vivaldi antenna (2), and is characterized in that the differential on-chip microstrip line-slot line switching structure (1) comprises a differential feed microstrip line (11) and an open-circuit slot line (12), and the on-chip Vivaldi antenna (2) is composed of a gradually-changed metal slot; and the on-chip Vivaldi antenna (2) is directly connected with the microstrip line-slot line switching structure. The input end of the differential on-chip microstrip line-slot line switching structure (1) is connected with the output ends of two paths of zero-degree power synthesis amplifiers, differential signals are loaded to a single-end open-circuit slot line (12) through a microstrip line (11), and the zero-degree power synthesis amplifiers are obtained through magnetic field and electric field energy conversion at a virtual point of the microstrip line (11) and an open-circuit slot line point. And a differential output signal in the microstrip line (11) is converted into the open-circuit slot line (12), so that broadband differential-single-ended conversion and power synthesis are realized.

Description

Technical Field

[0001] The present invention relates to a slot-line-based terahertz on-chip power synthesis structure, belonging to passive device and antenna technology in terahertz integrated circuits. Background Art

[0002] To meet the ultra-high capacity and transmission rate requirements of 6G networks, there is an urgent need to explore the millimeter wave and terahertz spectrum. Chips and devices are crucial to the development and utilization of these frequency bands. Within the sub-terahertz band, the J-band has attracted widespread attention due to its rich spectrum resources. Several silicon-based transceivers operating in this band with communication rates exceeding 10Gbps have demonstrated the feasibility of achieving high-speed communication in the sub-terahertz band. For 6G terahertz applications, phased array chips that support multi-beam capabilities are becoming increasingly important. However, as the operating frequency increases, the wavelength of the electromagnetic wave becomes shorter. At this time, the chip size cannot be ignored relative to the wavelength of the electromagnetic wave, which brings difficulties to the design of scalable phased array chips. In the present invention, a differential on-chip microstrip line-to-slotline transition structure and an on-chip Vivaldi antenna are used for power synthesis. The on-chip power synthesis structure proposed in the present invention is very compact, with a width less than half the operating wavelength, making it suitable for scalable phased arrays. Summary of the Invention

[0003] Technical Problem: Most terahertz transceivers operating above 200 GHz require on-chip antennas. Separately designing the power combining network from the on-chip antenna results in additional losses, impacting the system's bandwidth and EIRP. This invention aims to overcome these shortcomings by integrating the on-chip antenna with the on-chip power combining network, ultimately proposing a slotline-based terahertz on-chip power combining structure.

[0004] Technical solution: To achieve the above-mentioned purpose, the present invention provides a slotline-based terahertz on-chip power synthesis structure, which includes a differential on-chip microstrip line-slotline transition structure and an on-chip Vivaldi antenna: the differential on-chip microstrip line-slotline transition structure includes a differentially fed microstrip line and an open slotline, and the on-chip Vivaldi antenna is composed of a gradient metal slot, which is directly connected to the microstrip line-slotline transition structure.

[0005] The input end of the differential on-chip microstrip line-slot line transition structure is connected to the output end of two zero-degree power combining amplifiers. The differential characteristics of the output ends of the two zero-degree power combining amplifiers are utilized to load the differential signal onto the single-ended open slot line using a microstrip line. The magnetic field and electric field energy are converted between the virtual ground point of the microstrip line and the point of the open slot line, thereby converting the differential output signal in the microstrip line into the open slot line, thereby realizing broadband differential-to-single-ended conversion and power combining.

[0006] The on-chip Vivaldi antennas are arranged horizontally to realize a one-element linear array.

[0007] The microstrip line is a C-shaped structure, and both opening ends of the C-shaped structure are connected to the output ends of two zero-degree power synthesis amplifiers.

[0008] The open slot line is located in the microstrip line, and a large piece of metal is hollowed out at the left end of the open slot line to form a metal open structure.

[0009] The center of the open trench line structure is filled with dummy metal to meet semiconductor process manufacturing requirements.

[0010] The outer dimensions of the open slot line are 18×60 μm, and the width of the slot line is 5 μm.

[0011] The on-chip Vivaldi antenna is composed of a gradient metal slot, which is composed of multiple layers of metal. A row of straight slots is provided on both sides of the gradient metal slot.

[0012] The on-chip Vivaldi antenna has an opening width of 50 μm and a length of 475 μm.

[0013] The two-channel zero-degree power synthesis amplifier is a one-two power amplifier, the input end of the one-two power amplifier is connected to the mixer, and the input end of the mixer is connected to the intermediate frequency signal and the terahertz transmitter signal.

[0014] The present invention is based on a slotline-based terahertz on-chip power synthesis structure, including a differential on-chip microstrip line-slotline transition structure. This structure utilizes the natural differential characteristics of the output ends of two zero-degree power synthesis amplifiers, uses microstrip lines to load differential signals onto a single-ended open slotline, and converts the magnetic and electric field energy at the virtual ground points of the microstrip lines and the open points of the slotline to convert the differential output signals in the microstrip lines into the slotline, thereby realizing broadband differential-to-single-ended conversion and power synthesis.

[0015] The slotline-based terahertz on-chip power combining structure of the present invention also includes an on-chip Vivaldi antenna. This slotline-based Vivaldi antenna can be directly connected to a microstrip slotline transition structure without any impedance matching issues, and the Vivaldi antenna itself has a wide bandwidth. Furthermore, the horizontally arranged Vivaldi antenna can realize a single-element linear array.

[0016] Therefore, the slot-line-based terahertz on-chip power combining structure proposed in the present invention can realize broadband on-chip power combining compactly and is beneficial to chip arrays.

[0017] Beneficial effects: The slot-line-based terahertz on-chip power synthesis structure proposed in the present invention has the following advantages over the prior art:

[0018] 1. Existing terahertz on-chip power combining structures use a Marchand balun to convert differential signals into single-ended signals and output them to a 50-ohm load. However, the electromagnetic wave energy is concentrated in the microstrip line. If an end-fire on-chip antenna is designed to radiate the signal, an additional balun is required to convert the single-ended signal in the microstrip line back into a differential signal, which introduces additional insertion loss and degrades bandwidth. With the structure proposed in this invention, the signal only undergoes a single differential-to-single-ended conversion, and the inherent symmetry of the structure ensures its broadband characteristics.

[0019] Another existing terahertz on-chip power combining structure uses a single-ended microstrip line to directly excite a slot line, and then uses a Vivaldi antenna to radiate the terahertz signal. However, the inherent asymmetry of this circuit results in asymmetric current distribution on the two antenna walls, resulting in an asymmetric antenna beam. The structure proposed in this invention has inherent symmetry, ensuring a symmetric antenna beam. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a diagram of the terahertz on-chip power synthesis structure based on slot lines proposed in the present invention;

[0021] Figure 2 The structure diagram and simulation results of the differential on-chip microstrip line-slot line transition proposed by the present invention; Figure 2 (a) is the differential on-chip microstrip line-slot line transition structure diagram. Figure 2 (b) is the simulation result of the differential on-chip microstrip line-slot line transition structure.

[0022] Figure 3 A structural diagram of the Vivaldi antenna included in the present invention; Figure 3 (a) is the main structure of the Vivaldi antenna. Figure 3 (b) is the metal stacked structure of the Vivaldi antenna.

[0023] Figure 4 This is the simulation result of the Vivaldi antenna included in the present invention.

[0024] The figure shows: a differential on-chip microstrip line-slot line transition structure 1, an on-chip Vivaldi antenna 2, a microstrip line 11, an open slot line 12, and a straight slot 21. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings.

[0026] like Figure 1The present invention shows a slotline-based terahertz on-chip power synthesis structure, comprising a differential on-chip microstrip-to-slotline transition structure 1 and an on-chip Vivaldi antenna 2. The differential on-chip microstrip-to-slotline transition structure 1 comprises a differentially fed microstrip line 11 and an open slotline 12. The on-chip Vivaldi antenna 2 is formed of a gradient metal slot and is directly connected to the microstrip-to-slotline transition structure. The input end of the differential on-chip microstrip-to-slotline transition structure 1 is connected to the output ends of two zero-degree power synthesis amplifiers. The differential characteristics of the output ends of the two zero-degree power synthesis amplifiers are utilized to load the differential signal onto the single-ended open slotline 12 using the microstrip line 11. The differential output signal in the microstrip line 11 is converted to the open slotline 12 through the conversion of magnetic and electric field energy at the virtual point of the microstrip line 11 and the point of the open slotline, thereby achieving broadband differential-to-single-ended conversion and power synthesis. The on-chip Vivaldi antenna 2 is arranged horizontally, and can realize a one-element linear array.

[0027] The microstrip line 11 is a C-shaped structure, with its open ends connected to the outputs of two zero-degree power combining amplifiers. The open slot line 12 is located within the microstrip line 11. A large piece of metal is hollowed out at the left end of the open slot, forming a metal open circuit structure. The center of the open slot line structure 12 is filled with dummy metal to meet semiconductor manufacturing requirements. The open slot line 12 has dimensions of 18 x 60 μm and a slot width of 5 μm. The on-chip Vivaldi antenna 2 is formed by a tapered metal slot composed of multiple layers of metal, with a row of linear slots 21 on either side. The opening width of the on-chip Vivaldi antenna 2 is 50 μm and the length is 475 μm. The two zero-degree power combining amplifiers are two-way power amplifiers, each connected to a mixer. The mixer's inputs are connected to the intermediate frequency signal and the terahertz transmitter signal.

[0028] This structure utilizes the natural differential characteristics of the output ends of two zero-degree power combining amplifiers, uses microstrip lines to load differential signals onto single-ended open slot lines, and converts the magnetic and electric field energy at the virtual points of the microstrip lines and the open points of the slot lines to convert the differential output signals in the microstrip lines into the slot lines, thus realizing broadband differential-to-single-ended conversion and power combination.

[0029] Figure 2 The 3D layout and simulation results of the transfer structure are shown. Figure 2 As shown in (b), the insertion loss of this switching structure is only 1dB within a 70GHz bandwidth, and it has the characteristics of broadband low loss.

[0030] The slotline-based Vivaldi antenna can be directly connected to a microstrip slotline transition structure without any impedance matching problem, and the Vivaldi antenna itself has a wide bandwidth.

[0031] The size of the antenna is Figure 3 As shown,

[0032] The simulation results are as follows Figure 4 The antenna has a small gain fluctuation over a wide frequency range, demonstrating broadband characteristics.

[0033] The present invention connects the above two structures to form a terahertz on-chip power synthesis structure based on slot lines.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A terahertz on-chip power combining structure based on slot lines, characterized by: The invention comprises a differential on-chip microstrip line-slot line transition structure (1) and an on-chip Vivaldi antenna (2): the differential on-chip microstrip line-slot line transition structure (1) comprises a differentially fed microstrip line (11) and an open-circuit slot line (12); the on-chip Vivaldi antenna (2) is composed of a gradient metal slot; and the on-chip Vivaldi antenna (2) is directly connected to the microstrip line-slot line transition structure.

2. The slotline-based terahertz on-chip power combining structure according to claim 1, characterized in that: The input end of the differential on-chip microstrip line-slot line transition structure (1) is connected to the output ends of two zero-degree power synthesis amplifiers. The differential characteristics of the output ends of the two zero-degree power synthesis amplifiers are utilized to load the differential signal onto the single-ended open slot line (12) using a microstrip line (11). By converting the magnetic field and electric field energy at the virtual point of the microstrip line (11) and the open slot line point, the differential output signal in the microstrip line (11) is converted into the open slot line (12), thereby realizing broadband differential-single-ended conversion and power synthesis.

3. The slotline-based terahertz on-chip power combining structure according to claim 2, characterized in that: The on-chip Vivaldi antenna (2) is arranged horizontally, and can realize a one-element linear array.

4. The slotline-based terahertz on-chip power combining structure according to claim 2, characterized in that: The microstrip line (11) is a C-shaped structure, and both opening ends of the C-shaped structure are connected to the output ends of two zero-degree power synthesis amplifiers.

5. The slotline-based terahertz on-chip power combining structure according to claim 2, characterized in that: The open slot line (12) is located in the microstrip line (11), and a large piece of metal is hollowed out at the left end of the open slot line to form a metal open structure.

6. The slotline-based terahertz on-chip power combining structure according to claim 5, characterized in that: The center of the open-circuit slot line structure (12) is filled with dummy metal to meet semiconductor process manufacturing requirements.

7. The slotline-based terahertz on-chip power combining structure according to claim 5, characterized in that: The outer dimensions of the open-circuit slot line (12) are 18×60 μm, and the width of the slot line is 5 μm.

8. The slotline-based terahertz on-chip power combining structure according to claim 2, characterized in that: The on-chip Vivaldi antenna (2) is composed of a gradient metal slot, which is composed of multiple layers of metal. A row of linear slots (21) is provided on both sides of the gradient metal slot.

9. The slotline-based terahertz on-chip power combining structure according to claim 8, characterized in that: The on-chip Vivaldi antenna (2) has an opening width of 50 μm and a length of 475 μm.

10. The slotline-based terahertz on-chip power combining structure according to claim 2, characterized in that: The two-channel zero-degree power synthesis amplifier is a one-two power amplifier, the input end of the one-two power amplifier is connected to the mixer, and the input end of the mixer is connected to the intermediate frequency signal and the terahertz transmitter signal.

Images