Annular combined full-band terahertz even harmonic frequency multiplier

Abstract

The invention belongs to the technical field of terahertz communication, provides an annular combined full-band terahertz even harmonic frequency multiplier, and is used for solving the problem that a broadband frequency multiplier is relatively low in efficiency. The antenna comprises an input waveguide, an on-chip integrated circuit and an output waveguide, wherein the on-chip integrated circuit comprises an input probe, an input matching microstrip line, an annular combined structure, an output matching circuit and an output probe; the annular combined structure is formed by connecting two signal branches in parallel, each signal branch is formed by connecting a band-pass filter and a diode array in series, and the diode arrays in the two signal branches form an anti-parallel structure. An annular combined structure is provided, a high-frequency-band narrow-pass-band filter and a low-frequency-band narrow-pass-band filter are arranged on two signal branches of the annular combined structure respectively, signals are improved from full-frequency-band filtering to two narrow-band filtering, and finally the two narrow-band signals are combined into a broadband signal. Therefore, the full-band frequency multiplication efficiency of the device is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of terahertz communication, relates to a frequency multiplier structure, and specifically provides a ring-shaped combined full-band terahertz even-harmonic frequency multiplier. Background Art

[0002] At present, most of the research on terahertz frequency multipliers is mainly aimed at full-band and high-efficiency directions, but the efficiency of full-band frequency multipliers is low and the bandwidth of high-efficiency frequency multipliers is narrow. Terahertz frequency multipliers mainly use the nonlinear characteristics of Schottky diodes to generate various harmonic components, and then the desired frequency multiplier signal appears. Then the target frequency multiplier signal is filtered through subsequent means, and then the frequency multiplier signal is output; the design difficulty of the frequency multiplier mainly lies in the two parts of the filter and Schottky diode. The performance of the filter will directly affect the bandwidth of the frequency multiplier and the degree of interference of other signals on the fundamental signal. The filter with excellent performance needs to have low insertion loss in the passband and high suppression ability in the stopband. Generally, wide passband filters are more difficult to design and have greater insertion loss than narrow passband filters. Therefore, the efficiency of broadband frequency multipliers is generally lower than that of narrowband frequency multipliers. Summary of the invention

[0003] The purpose of the present invention is to provide a ring-type combined full-band terahertz even-harmonic frequency multiplier to address the problem of low efficiency of broadband frequency multipliers, which effectively combines the advantages of full-band mixers and high-efficiency mixers to achieve higher conversion efficiency in a wide bandwidth.

[0004] To achieve the above purpose, the beneficial effects of the present invention are:

[0005] A ring-shaped combined full-band terahertz even-harmonic frequency multiplier comprises: an input waveguide 1, an on-chip integrated circuit 2 and an output waveguide 3, characterized in that the on-chip integrated circuit comprises: an input probe 21, an input matching microstrip line 22, a ring-shaped combined structure 23, an output matching circuit 24 and an output probe 25 connected in sequence; the ring-shaped combined structure 23 is composed of two signal branches in parallel, each signal branch is composed of a bandpass filter 231 and a diode array 232 in series, and the diode arrays in the two signal branches form an anti-parallel structure.

[0006] Furthermore, in the ring combination structure, the passband of the bandpass filter on a signal branch is f min ~f a , the passband of the bandpass filter on the other signal branch is f b ~f max , 0.9f a ≤f b ≤f a , f min is the minimum operating frequency of the frequency multiplier, f maxis the maximum operating frequency of the frequency multiplier, f a is 180GHz, f b It is 180GHz.

[0007] Furthermore, in the ring structure, f a =f b =(f max -f min ) / 2.

[0008] Furthermore, the input waveguide is composed of a standard input waveguide and an input height-reducing waveguide, and the standard input waveguide adopts a standard rectangular waveguide WR-5; the input fundamental wave signal is input from the standard input waveguide, and after passing through the input height-reducing waveguide, it is coupled to the input matching microstrip line 22 by the input probe 21, and then enters the annular combination structure 23 for frequency doubling.

[0009] Furthermore, the output waveguide includes: a standard output waveguide and an output height-reducing waveguide, the standard output waveguide adopts a standard rectangular waveguide WR-10; the even harmonic signal output by the annular combination structure 23 is coupled to the output height-reducing waveguide by the output probe 25 through the output matching circuit 24, and then the even harmonic doubled frequency signal is output by the standard output waveguide.

[0010] Furthermore, in the ring combination structure, the bandpass filter adopts a CMRC filter and a high and low impedance filter.

[0011] Furthermore, the diode array includes: N Schottky diodes connected in series, N≥6; the Schottky diode loop is combined with the filter loop to realize a nonlinear frequency conversion network. The more diodes there are, the higher the frequency multiplication power that can be tolerated, and adaptive adjustment is performed according to actual needs.

[0012] Furthermore, the input probe adopts an E-plane probe, and the output probe adopts an E-plane probe.

[0013] Based on the above technical solution, the beneficial effects of the present invention are:

[0014] The present invention provides a ring-shaped combined full-band terahertz even-harmonic frequency multiplier, which uses a nonlinear Schottky diode as a core component, improves the traditional structure of a fundamental wave filter circuit and an anti-parallel diode, proposes a ring-shaped combined structure, and respectively sets a high-frequency narrow passband filter and a low-frequency narrow passband filter on two signal branches of the ring-shaped combined structure, improves the signal from full-band filtering to two narrow-band filtering, and finally merges the two narrow-band signals into a broadband signal, thereby improving the full-band frequency multiplication efficiency of the device. The signal is input from an input waveguide and coupled to a cavity microstrip line, and the required signal frequency band is retained after matching, and the nonlinearity of the diode is used to obtain a second harmonic signal while passing through a filter to obtain a harmonic signal, and finally output through an output waveguide. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural diagram of the annular combined full-band terahertz even-harmonic frequency multiplier of the present invention;

[0016] Figure 2 It is a schematic diagram of the structure of an on-chip integrated circuit of a ring-shaped combined full-band terahertz even-harmonic frequency multiplier in the present invention;

[0017] Figure 3 It is a schematic diagram of the principle of the annular combined full-band terahertz even-harmonic frequency multiplier in the present invention;

[0018] Figure 4 It is a schematic structural diagram of the first annular combination structure of the annular combination type full-band terahertz even-harmonic frequency multiplier in the present invention;

[0019] Figure 5 It is a structural schematic diagram of a second annular combination structure of the annular combination type full-band terahertz even-harmonic frequency multiplier in the present invention;

[0020] Figure 6 It is a schematic structural diagram of a third annular combination structure of the annular combination type full-band terahertz even-harmonic frequency multiplier in the present invention;

[0021] Figure 7 The filtering performance of two narrowband filters when separated;

[0022] Figure 8 The performance of a broadband filter formed by connecting filters in parallel in a ring structure;

[0023] Among them, 1 is an input waveguide, 2 is an on-chip integrated circuit, 3 is an output waveguide, 21 is an input probe, 22 is an input matching microstrip line, 23 is a ring combination structure, 24 is an output matching circuit, 25 is an output probe, 231 is a bandpass filter, and 232 is a diode array in series. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0025] This embodiment provides a ring-type combined full-band terahertz even-harmonic frequency doubler with a frequency range of 145 to 220 GHz. The specific structure is as follows: Figure 1As shown, it includes: an input waveguide 1, an on-chip integrated circuit 2 and an output waveguide 3, the input waveguide includes: a standard input waveguide and an input height-reducing waveguide, the output waveguide includes: a standard output waveguide and an output height-reducing waveguide, the on-chip integrated circuit includes: an input probe 21, an input matching microstrip line 22, a ring combination structure 23, an output matching circuit 24 and an output probe 25; the input fundamental wave signal is input from the standard input waveguide, and after passing through the input height-reducing waveguide, it is coupled to the input matching microstrip line 22 by the input probe 21, and then enters the ring combination structure 23 for frequency doubling, the second harmonic signal output by the ring combination structure 23 passes through the output matching circuit 24 and is coupled to the output height-reducing waveguide by the output probe 25, and finally the doubled frequency signal is output by the standard output waveguide.

[0026] Specifically, the annular combination structure 23 is composed of two signal branches connected in parallel, each signal branch is composed of a bandpass filter 231 and a diode array 232 in series, and the diode arrays in the two signal branches form an anti-parallel structure; the passband of the bandpass filter on one of the two signal branches is f min ~f a , the passband of the bandpass filter on the other signal branch is f b ~f max , 0.9f a ≤f b ≤f a , f min is the minimum operating frequency of the frequency multiplier, f max is the maximum operating frequency of the frequency multiplier. After actual performance test and adjustment, the final result is f a =181GHz, f b =179GHz; in the two signal branches, the diode array generates harmonics through nonlinear characteristics. Since the two diode arrays are opposite in signal transmission direction, the odd harmonics are cancelled out in the ring combination structure, and the remaining even harmonics are combined into a broadband signal by two narrowband signals after passing through the ring combination structure, thus realizing full-band terahertz even harmonic frequency doubling; Figure 7 The performance of two independently designed simplex CMRC bandpass filters is shown in FIG. Figure 8 The figure shows the comprehensive filtering performance of the filter of the ring structure in the present invention. By comparison, it can be seen that the filtering bandwidth of the ring combination structure can cover the full frequency band of 145 to 220 GHz, and the filtering effect can also reach that of a narrowband filter, basically achieving filtering below -20 dB.

[0027] In addition, it should be noted that:

[0028] First, the core creativity of the present invention is to combine two narrowband signals into a broadband signal through a ring combination structure to achieve full-bandwidth. Therefore, in the optimal design of the frequency multiplier, the passbands of the bandpass filters on the two signal branches are as narrow as possible, so f a With f b Preferably located at (f max -f min ) / 2, or even f a =f b =(f max -f min ) / 2; Figure 4 As shown, in this embodiment, the passband of the upper bandpass filter is 145-180 GHz, and the passband of the lower bandpass filter is 180-220 GHz. By combining two narrowband signals into a broadband signal, a full-band doubler of 145-220 GHz is obtained.

[0029] Secondly, in each signal branch of the annular combination structure of the present invention, there is no order restriction for the filter and the diode array, that is, from the perspective of signal transmission direction, the filter and the diode array can be connected in series in sequence, the diode array and the filter can be connected in series in sequence, or the filter can be connected between multiple diodes in the diode array. Figure 4 , Figure 5 , Figure 6 As shown, this embodiment exemplarily provides three possible annular combination structures.

[0030] Specifically, the input probe adopts an E-plane probe, and the output probe adopts an E-plane probe; the standard input waveguide adopts a standard rectangular waveguide WR-5, and the standard output waveguide adopts a standard rectangular waveguide WR-10; the filter in the ring combination structure adopts a CMRC filter; the diode adopts a Schottky diode, and the nonlinear characteristics of the Schottky diode are used to generate even harmonic signals.

[0031] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A ring-type combined full-band terahertz even-harmonic frequency multiplier, comprising: An input waveguide (1), an on-chip integrated circuit (2) and an output waveguide (3), characterized in that the on-chip integrated circuit comprises: an input probe (21), an input matching microstrip line (22), a ring combination structure (23), an output matching circuit (24) and an output probe (25) connected in sequence; the ring combination structure (23) is composed of two signal branches connected in parallel, each signal branch is composed of a bandpass filter (231) and a diode array (232) connected in series, and the diode arrays in the two signal branches form an anti-parallel structure.

2. According to claim 1, the annular combined full-band terahertz even-harmonic frequency multiplier is characterized in that: In the ring combination structure, the passband of the bandpass filter on a signal branch is f min ~f a , the passband of the bandpass filter on the other signal branch is f b ~f max , 0.9f a ≤f b ≤f a , f min is the minimum operating frequency of the frequency multiplier, f max is the maximum operating frequency of the frequency multiplier, f a is the upper cutoff frequency of the low-frequency bandpass filter, f b It is the lower cut-off frequency of the high-frequency band-pass filter.

3. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 2, characterized in that: In the ring structure, f a =f b =(f max -f min ) / 2.

4. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 1, characterized in that: The input waveguide is composed of a standard input waveguide and an input height-reducing waveguide, wherein the standard input waveguide adopts a standard rectangular waveguide WR-5; the input fundamental wave signal is input from the standard input waveguide, and after passing through the input height-reducing waveguide, is coupled to the input matching microstrip line (22) by an input probe (21), thereby entering the annular combination structure (23) for frequency doubling.

5. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 1, characterized in that: The output waveguide comprises: a standard output waveguide and an output height-reducing waveguide, wherein the standard output waveguide adopts a standard rectangular waveguide WR-10; the even harmonic signal output by the annular combination structure (23) is coupled to the output height-reducing waveguide by an output probe (25) through an output matching circuit (24), and then the even harmonic frequency-doubled signal is output by the standard output waveguide.

6. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 1, characterized in that: In the ring combination structure, the bandpass filter adopts CMRC filter and high and low impedance filter.

7. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 1, characterized in that: The diode array includes: N Schottky diodes connected in series, where N is greater than or equal to 6.

8. The annular combined full-band terahertz even-harmonic frequency multiplier according to claim 1, characterized in that: The input probe uses an E-plane probe, and the output probe uses an E-plane probe.

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