A high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT

Abstract

The invention discloses a terahertz frequency doubler based on microstrip line and InP-HEMT, comprising a signal input port, a signal output port and a high electron mobility transistor, the source of the transistor is grounded, the gate of the transistor is connected to one end of the gate microstrip transmission line, the other end of the gate microstrip transmission line is connected to the output signal quarter-wavelength microstrip line, the input signal quarter-wavelength microstrip line and one end of the input matching network, the drain of the high electron mobility transistor is connected to one end of the drain microstrip transmission line, the other end of the drain transmission line is connected to the input signal quarter-wavelength microstrip line, the output signal quarter-wavelength microstrip line and one end of the output matching network, the other end of the input signal quarter-wavelength microstrip line is open, and the other end of the output signal quarter-wavelength microstrip line is connected to the output signal quarter-wavelength double fan-shaped open line and one end of the drain power supply microstrip line. The frequency doubling efficiency of the invention is high, and the working bandwidth is wide.

Description

Technical Field

[0001] The present invention relates to the technical field of terahertz communication, and in particular to a terahertz frequency doubler based on a microstrip line and InP-HEMT. Background Art

[0002] A frequency multiplier is a device that multiplies the frequency of a signal by an integer multiple. Frequency multipliers are very common in high-frequency communication links. In today's booming terahertz communication systems, in order to obtain a stable and reliable terahertz frequency source, it is very common to use a frequency multiplier to multiply a relatively low-frequency signal source to the terahertz frequency band, which greatly increases the transmission rate of information.

[0003] Frequency multipliers mainly include varactor diode frequency multipliers, planar Schottky diode frequency multipliers, step recovery diode frequency multipliers, and FET frequency multipliers. Although the devices and structures used in these frequency multipliers are different, their working principles are to use the nonlinear characteristics of the devices to generate high-order harmonics, extract the target order high-order harmonics through a specific circuit structure, and filter out unnecessary harmonics and fundamental waves. The performance indicators of the frequency multiplier mainly depend on the conversion gain and efficiency. The conversion efficiency of the varactor diode frequency multiplier is low, and it is easy to generate large frequency multiplication noise; the frequency multiplication efficiency of the planar Schottky diode frequency multiplier is low; the step recovery diode frequency multiplier circuit is unstable; and the circuit structure of the FET frequency multiplier is complex. Summary of the invention

[0004] In view of the above problems or shortcomings, the present invention proposes a high-efficiency terahertz doubler based on microstrip line and InP-HEMT, which has simple structure, is easy to process, has high efficiency and wide bandwidth.

[0005] In order to achieve the above-mentioned purpose, the technical scheme of the present invention is: a high-efficiency terahertz doubler based on microstrip line and InP-HEMT, comprising a signal input port, a signal output port and a high electron mobility transistor, the source of the transistor is grounded, the gate of the transistor is connected to one end of the gate microstrip transmission line, the other end of the gate microstrip transmission line is connected to the output signal quarter-wavelength microstrip line, the input signal quarter-wavelength microstrip line and one end of the input matching network, the other end of the output signal quarter-wavelength microstrip line is open, the other end of the input signal quarter-wavelength microstrip line is connected to the input signal quarter-wavelength double-fan-shaped open line and the gate power supply microstrip line, the other end of the gate power supply microstrip line is connected to the gate power supply, the drain of the high electron mobility transistor is connected to one end of the drain microstrip transmission line, the other end of the drain transmission line is connected to the input signal quarter-wavelength microstrip line, the output signal quarter-wavelength microstrip line and one end of the output matching network, the other end of the input signal quarter-wavelength microstrip line is open, the other end of the output signal quarter-wavelength microstrip line is connected to the output signal quarter-wavelength double-fan-shaped open line and the drain power supply microstrip line, and the other end of the drain power supply microstrip line is connected to the drain power supply.

[0006] Furthermore, the input matching network operates at the fundamental frequency, and the input matching network is formed by connecting one end of three microstrip lines together to form a T-type network, wherein the other end of one of the microstrip lines is open, and the other end of the input matching network is connected to one end of an input DC blocking capacitor, and the input DC blocking capacitor is used to isolate the DC signal from flowing into the signal input port.

[0007] Furthermore, the signal input port is connected to the other end of the input DC blocking capacitor, and the high-frequency input signal is input from the input signal port and passes through the input DC blocking capacitor to the input matching circuit.

[0008] Furthermore, the output matching network operates at the second harmonic frequency, and the output matching network is formed by connecting one end of three microstrip lines together to form a T-type network, wherein the other end of one of the microstrip lines is open, and the other end of the output matching network is connected to one end of an output DC blocking capacitor, and the output DC blocking capacitor is used to isolate the DC signal from flowing into the output signal port.

[0009] Furthermore, the signal output port is connected to the other end of the output DC-isolating capacitor, and the doubled frequency output signal passes through the output DC-isolating capacitor and is output from the signal output port.

[0010] Furthermore, the two fan-shaped microstrip lines of the input signal quarter-wavelength double fan-shaped open line are respectively connected to both sides of the end of the input signal quarter-wavelength microstrip line, which can greatly broaden the bandwidth of the input signal and reduce the loss of the input signal.

[0011] Furthermore, the two fan-shaped microstrip lines of the output signal quarter-wavelength double fan-shaped open line are respectively connected to both sides of the end of the output signal quarter-wavelength microstrip line, which can greatly broaden the bandwidth of the output signal and reduce the loss of the output signal.

[0012] Furthermore, the gate power supply supplies power to the gate, so that the high electron mobility transistor operates in class B.

[0013] Furthermore, the high electron mobility transistor adopts InP-HEMT, and all microstrip lines and capacitors are made on the same single chip with the high electron mobility transistor HEMT, so that the processing is precise.

[0014] The present invention has the following effects:

[0015] (1) Compared with other frequency multipliers, the processing accuracy is high, avoiding the welding error of independent components.

[0016] (2) The present invention has high frequency doubling efficiency and wide bandwidth, and avoids the use of filters, so the loss is small.

[0017] (3) The structure of the present invention is simple. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the circuit structure of the present invention;

[0019] Figure 2 It is a schematic diagram of the connection between the double fan-out line and the quarter-wavelength microstrip line of the present invention;

[0020] Figure 3 This is a simulation diagram of the frequency doubling signal efficiency of the present invention;

[0021] Figure 4 This is a simulation diagram of the frequency-doubled signal output power of the present invention; DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments:

[0023] like Figure 1As shown, the high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT provided in this embodiment includes a signal input port, a signal output port and a high electron mobility transistor HEMT, the source of the transistor is grounded, the gate of the transistor is connected to one end of the gate microstrip transmission line MLIN3, the other end of the gate microstrip transmission line MLIN3 is connected to the output signal quarter-wavelength microstrip line MLIN8, the input signal quarter-wavelength microstrip line MLIN11 and one end of the input matching network, the other end of the output signal quarter-wavelength microstrip line MLIN8 is open, and the other end of the input signal quarter-wavelength microstrip line MLIN11 is connected to the input signal quarter-wavelength double fan-shaped open line 1 and the gate power supply microstrip line MLIN8. strip line MLIN13, the other end of the gate power supply microstrip line MLIN13 is connected to the gate power supply power supply, the drain of the high electron mobility transistor HEMT is connected to one end of the drain microstrip transmission line MLIN4, the other end of the drain microstrip transmission line MLIN4 is connected to the input signal quarter-wavelength microstrip line MLIN9, the output signal quarter-wavelength microstrip line MLIN12 and one end of the output matching network, the other end of the input signal quarter-wavelength microstrip line MLIN9 is open, the other end of the output signal quarter-wavelength microstrip line MLIN12 is connected to the output signal quarter-wavelength double-fan open line 2 and the drain power supply microstrip line MLIN14, and the other end of the drain power supply microstrip line MLIN14 is connected to the drain power supply power supply.

[0024] In this embodiment, the input matching network is formed by connecting three microstrip lines MLIN1, MLIN2, and MLIN7. The input matching network matches the input impedance to 50 ohms of the fundamental frequency. The impedance of the signal input port is also 50 ohms. The fundamental power output by the signal input port is 11 dBm. The capacitance of the input isolation capacitor C1 is 1 pF. The input DC isolation capacitor prevents the DC current of the gate power supply from flowing to the signal input port while allowing the high-frequency fundamental signal to pass through. The signal input port inputs the fundamental signal with a frequency of 70 GHz to the gate of the high electron mobility transistor HEMT through the input DC isolation capacitor C1, the input matching network, and the gate microstrip transmission line MLIN3.

[0025] In this embodiment, the output matching network is formed by connecting three microstrip lines MLIN5, MLIN6, and MLIN10. The output matching network matches the output impedance to 50 ohms of the second harmonic frequency. The impedance of the signal input and output port is also 50 ohms. The capacitance of the input isolation capacitor C2 is 1 pF. The output DC isolation capacitor prevents the DC current of the drain power supply from flowing to the signal output port while allowing the high-frequency second harmonic signal to pass through. The second harmonic signal is output from the drain of the high electron mobility transistor HEMT and reaches the signal output port through the output matching network and the output DC isolation capacitor.

[0026] In this embodiment, the connection diagram of the input signal quarter-wavelength double fan-shaped open line 1 and the input signal quarter-wavelength microstrip line MLIN11, the output signal quarter-wavelength double fan-shaped open line 2 and the output signal quarter-wavelength microstrip line MLIN12 is shown in FIG. Figure 2 As shown, this can effectively expand the bandwidth of the input signal and the bandwidth of the output signal and reduce signal loss.

[0027] In this embodiment, the high electron mobility transistor HEMT uses InP-HEMT, so that the circuit can operate at an extremely high frequency. The gate bias voltage is -1.2V, so that the high electron mobility transistor HEMT operates in Class B, so that rich harmonics can be output at the drain of the high electron mobility transistor HEMT. The high electron mobility transistor uses InP-HEMT, and all the microstrip lines and capacitors mentioned above are made on the same single chip as the high electron mobility transistor HEMT.

[0028] The simulation results of this embodiment are as follows Figure 3 , Figure 4 As shown, the maximum second harmonic output power is 13.867dBm, and the frequency band in which the double frequency efficiency exceeds 100% is 142.4GHz-150GHz.

[0029] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. A high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT, comprising a signal input port, a signal output port and a high electron mobility transistor, wherein the source of the transistor is grounded, the gate of the transistor is connected to one end of a gate microstrip transmission line, the other end of the gate microstrip transmission line is connected to an output signal quarter-wavelength microstrip line, an input signal quarter-wavelength microstrip line and one end of an input matching network, the other end of the output signal quarter-wavelength microstrip line is open-circuited, the other end of the input signal quarter-wavelength microstrip line is connected to an input signal quarter-wavelength double-fan-shaped open line and a gate power supply microstrip line, the other end of the gate power supply microstrip line is connected to a gate power supply, the drain of the high electron mobility transistor is connected to one end of a drain microstrip transmission line, the other end of the drain transmission line is connected to an input signal quarter-wavelength microstrip line, an output signal quarter-wavelength microstrip line and one end of an output matching network, the other end of the input signal quarter-wavelength microstrip line is open-circuited, the other end of the output signal quarter-wavelength microstrip line is connected to the output signal quarter-wavelength double-fan-shaped open line and a drain power supply microstrip line, and the other end of the drain power supply microstrip line is connected to a drain power supply.

2. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The input matching network operates at the fundamental frequency. The input matching network is formed by connecting one end of three microstrip lines together to form a T-type network, the other end of one microstrip line is open, and the other end of the input matching network is connected to one end of the input DC blocking capacitor.

3. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The signal input port is connected to the other end of the input DC blocking capacitor.

4. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The output matching network operates at the second harmonic frequency. The output matching network is formed by connecting one end of three microstrip lines together to form a T-type network, the other end of one microstrip line is open, and the other end of the output matching network is connected to one end of the output DC blocking capacitor.

5. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The signal output port is connected to the other end of the output DC blocking capacitor.

6. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The two fan-shaped microstrip lines of the input signal quarter-wavelength double fan-shaped open line are respectively connected to the two sides of the end of the input signal quarter-wavelength microstrip line.

7. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The two fan-shaped microstrip lines of the output signal quarter-wavelength double fan-shaped open line are respectively connected to the two sides of the end of the input signal quarter-wavelength microstrip line.

8. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The gate power supply supplies power to the gate, so that the high electron mobility transistor operates in class B.

9. The high-efficiency terahertz frequency doubler based on microstrip line and InP-HEMT according to claim 1, characterized in that: The high electron mobility transistor adopts InP-HEMT, and all microstrip lines and capacitors are made on the same single chip as the high electron mobility transistor.

Images