Comb spectrum generator

Abstract

A comb spectrum generator comprises a nonlinear transmission line circuit connected between a signal input end and a signal output end, and further comprises an input series matching circuit, the input end of the input series matching circuit is connected to the signal input end, and the output end of the input series matching circuit is connected to the nonlinear transmission line circuit, the input series matching circuit includes at least one first inductor and at least one first capacitor connected in series with the first inductor. According to the comb spectrum generator, the input series matching circuit is arranged at the front end of the nonlinear transmission line circuit, so that echo reflection generated in the comb spectrum generator after a high-power signal is input in a target input frequency range can be reduced; a high-power input signal can enter the nonlinear transmission line circuit without loss as far as possible, so that the high-power input signal is effectively converted into higher harmonic output, and the power conversion rate of the high-power input signal is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of comb spectrum generator, concretely relates to a nonlinear transmission line (NLTL) comb spectrum generator that improves harmonic output power through narrow -band high -power signal input matching. BACKGROUND

[0002] A nonlinear transmission line (NLTL) is generally an inductance-capacitance (LC) ladder network that includes periodically loaded nonlinear elements, such as nonlinear inductors or nonlinear capacitors. For example, the periodically loaded nonlinear capacitors in a NLTL can be reverse-biased varactor diodes or Schottky diodes. NLTLs have been widely used in device and system applications, including comb spectrum generators, time domain reflectometers (TDRs), frequency synthesizers, frequency multipliers, high-speed sampling oscilloscopes, pulse generators, and the like.

[0003] A comb spectrum generator is a kind of harmonic signal generator, and the output signal has a series of harmonic components of the input signal, and each harmonic component has significant signal power. This output signal usually includes a series of uniformly spaced spectral components, so that the spectrum of the output signal resembles the teeth of a comb. Comb spectrum generators based on nonlinear transmission line technology have been proven to improve phase noise and expand the input power range.

[0004] When the input of the comb spectrum generator is a continuous wave signal with a frequency of f, the frequency spectrum of the output signal of the comb spectrum generator is the integer harmonic n*f (n=1, 2, 3…) of the input frequency f, and usually the output power of the corresponding harmonic frequency decreases more as the multiple n value increases. It is challenging to make the power spectrum of the output signal of the comb spectrum generator flat and high.

[0005] The inventor disclosed a NLTL comb spectrum generator in patent CN115940885A, the inductance-capacitance cascade network of the NLTL has a wideband characteristic, and its input frequency range is wide, for example, it has a better input standing wave characteristic (S11 better than -10dB) in the input frequency range of 0.1-5.0GHz, so the NLTL comb spectrum generator realizes input and output impedance matching on a wide band by coupling a bias circuit on the signal propagation path. However, this input matching method on a wide band is only suitable for impedance matching of small signals with low input power, and under the condition of a high-power input signal at a specific frequency point (for example, the input signal power is higher than 15dBm), the harmonic output power of the output signal is low, and the output power conversion efficiency of the existing NLTL comb spectrum generator needs to be further improved. UTILITY MODEL CONTENTS

[0006] The utility model discloses a comb spectrum generator, it is through connecting input series matching circuit in the front end of nonlinear transmission line (NLTL) circuit, can carry out power conversion efficiency matching to the high power signal of input power in the target input frequency range narrower than the frequency range of NLTL circuit, thereby improve the power conversion efficiency in target output frequency point or target output frequency range, improve harmonic output power.

[0007] The present application is realized by the following technical solutions:

[0008] A comb spectrum generator comprises a nonlinear transmission line circuit connected between a signal input end and a signal output end, and further comprises an input series matching circuit, an input end of the input series matching circuit being connected to the signal input end, and an output end of the input series matching circuit being connected to the nonlinear transmission line circuit, wherein the input series matching circuit comprises at least one first inductor and at least one first capacitor connected in series with the first inductor.

[0009] In the present technical solution, the comb spectrum generator comprises a nonlinear transmission line (NLTL) circuit arranged between a signal input end and a signal output end. The signal input end is configured to receive an input high power signal, the input high power signal having an input power of no less than 15 dBm. The NLTL circuit is configured to generate an output signal based on the input high power signal. The output signal is finally output via the signal output end, and the output signal comprises a plurality of harmonics of the input high power signal. In one or more embodiments, the NLTL circuit can adopt any one of the periodic circuit structures comprising a series inductor and a parallel variable capacitor disclosed in the prior art, such as patent CN115940885A. The periodic circuit structure of the NLTL is approximately equivalent to a transmission line model, and therefore naturally has a very wide input bandwidth.

[0010] In view of the difficulty in ensuring sufficient harmonic output power of the input high-power signal in a narrower target input frequency range when input matching is performed in a wider frequency range, the technical solution differs from the prior art in that it further comprises an input series matching circuit connected between the signal input end and the nonlinear transmission circuit, which is used to change the broadband matching performance of the nonlinear transmission line circuit, so that the input signal at the preset target input frequency point f0 or the input signal in the target input frequency range (f1, f2) containing the frequency point f0 has higher input power conversion efficiency at the target output frequency point or the target output frequency range compared with the nonlinear transmission line circuit without the input power conversion efficiency matching circuit. The input power conversion efficiency refers to the degree of effective conversion of the energy of the input signal into the harmonic output at the target output frequency point or the target output frequency range when the input signal enters the nonlinear transmission line circuit. When the input signal power is constant, the higher the harmonic power output at the target output frequency point or the target output frequency range, the higher the input power conversion efficiency.

[0011] In the technical solution, the input end of the input series matching circuit is connected to the signal input end, and the output end of the input series matching circuit is connected to the nonlinear transmission line circuit. The input series matching circuit at least comprises a first inductor and a first capacitor, and the first inductor and the first capacitor are connected in series. In some embodiments, the input series matching circuit comprises a first inductor and a first capacitor, wherein one end of the first capacitor is connected to the signal input end, the other end of the first capacitor is connected to the first inductor, and the first inductor is connected to the nonlinear transmission line circuit.

[0012] In addition, the bonding wire of the input end should also be considered as an equivalent inductance in the circuit. In one or more embodiments, the input series matching circuit comprises more than one inductor to achieve power conversion efficiency matching of a specific target input frequency range.

[0013] In the technical solution, the input high-power signal refers to an input signal with an input power not lower than 15 dBm, and in some preferred embodiments, the input high-power signal can be an input signal with a power greater than 18 dBm. The input high-power signal has a target input frequency range f∈(f1, f2) that is narrower than the bandwidth of the NLTL circuit, where f1 and f2 are the lowest frequency and the highest frequency containing the frequency point f0, respectively.

[0014] Specifically, f1 and f2 are the input frequency ranges with higher input power conversion efficiency after input power conversion efficiency matching according to the value of f0 compared with when the input series matching circuit is not connected.

[0015] In some preferred embodiments, the bandwidth of the target input frequency range satisfies (f2-f1) / f0≤25%. For example, in one or more embodiments, where f0 is any preset or specified frequency value, such as 850MHz, 1GHz or 2GHz. At this time, the target input frequency range of the input high-power signal is the frequency range containing f0 (such as 1GHz) which still has higher input power conversion efficiency compared to the NLTL circuit.

[0016] In the technical solution, the input series matching circuit is used to match the input high-power signal in the target input frequency range, to reduce the echo reflection generated inside the comb spectrum generator after the input of the input high-power signal in the target input frequency range, so that when the input frequency of the input high-power signal is in the target input frequency range, the input high-power signal can enter the nonlinear transmission line circuit as much as possible without loss, thereby effectively converting into high-order harmonic output and improving the power conversion rate of the input high-power signal.

[0017] As a preferred embodiment of the utility model, the comb spectrum generator further comprises an input parallel matching circuit to further improve the input power conversion efficiency. Specifically, one end of the input parallel matching circuit is connected in parallel between the input series matching circuit and the nonlinear transmission line circuit, and the other end of the input parallel matching circuit is grounded, wherein the input parallel matching circuit comprises at least one second capacitor.

[0018] In the technical solution, the input parallel matching circuit and the input series matching circuit constitute an input power conversion efficiency matching circuit together, wherein the input end of the input series matching circuit is connected to the signal input end, the output end of the input series matching circuit is connected to the nonlinear transmission line circuit, one end of the input parallel matching circuit is connected in parallel between the series matching circuit and the nonlinear transmission line circuit, and the other end of the input parallel matching circuit is grounded.

[0019] In the technical solution, the input parallel matching circuit comprises at least one second capacitor, which can be a variable capacitor such as a varactor diode, or a combination of a fixed capacitor and a variable capacitor. In some preferred embodiments, the input parallel matching circuit comprises one second capacitor. In one or more embodiments, the input parallel matching circuit can comprise multiple capacitors to achieve power conversion efficiency matching for a specific target input frequency range.

[0020] Further, an output matching circuit is further connected to the rear end of the NLTL circuit to optimize and match the target output frequency range, to reduce the output echo loss, so that the harmonics in the target output frequency range can be better output, further improving the harmonic output power.

[0021] Specifically, an output matching circuit is arranged between the nonlinear transmission line circuit and the signal output end, the output matching circuit comprises an output series matching circuit and an output series-parallel matching circuit, one end of the output series-parallel matching circuit is connected between the nonlinear transmission line circuit and the output series matching circuit, and the other end of the output series-parallel matching circuit is grounded; wherein the output series matching circuit comprises at least one third inductor and at least one third capacitor, and the third capacitor is connected in series to the third inductor; the output series-parallel matching circuit comprises at least one fourth inductor and at least one fourth capacitor, and the fourth capacitor is connected in parallel to the fourth inductor.

[0022] In the technical solution, the output matching circuit is used for impedance matching of harmonics in a target output frequency range. Preferably, the target output frequency range is an output frequency index set for the comb spectrum generator, which contains two or more than two harmonics of the input signal frequency.

[0023] In the technical solution, the input end of the output matching circuit is connected to the nonlinear transmission line circuit, and the output end of the output matching circuit is connected to the signal output end. The output matching circuit is used for optimized matching of the target output frequency range, reduces the output return loss, and enables better output of the harmonics in the frequency range, thereby further improving the harmonic output power. For example, when the input signal frequency of the comb spectrum generator is 1 GHz, and the target output frequency range is 8-20 GHz (i.e. 8th to 20th harmonics of 1 GHz), the output matching circuit is used to ensure that the harmonics in the target output frequency range are output as much as possible without loss.

[0024] In the technical solution, the output series matching circuit and the output series-parallel matching circuit constitute a band-pass filter network, and the target output frequency range falls within the passband range of the band-pass filter network. The output series matching circuit comprises at least one third inductor and one third capacitor, and the third inductor and the third capacitor are connected in series. In some preferred embodiments, the output series matching circuit comprises one third inductor and one third capacitor connected in series to the third inductor, one end of the third capacitor is connected to the output end of the output series-parallel matching circuit, the other end of the third capacitor is connected to the third inductor, and the third inductor is connected to the signal output end, wherein the third inductor is a bond wire equivalent inductor.

[0025] In the technical solution, the output series-parallel matching circuit comprises at least one fourth inductor and one fourth capacitor. The fourth inductor is connected in series between the nonlinear transmission line circuit and the output series matching circuit. One end of the fourth capacitor is connected in parallel between the fourth inductor and the output series matching circuit, and the other end of the fourth capacitor is grounded. In some preferred embodiments, the output series-parallel matching circuit comprises one fourth inductor and one fourth capacitor. In one or more embodiments, the fourth capacitor can be a variable capacitor such as a varactor diode, or a combination of a fixed capacitor and a variable capacitor.

[0026] In the technical solution, the output matching circuit is used to ensure that the combline spectrum generator outputs in a wide target output frequency range and has higher output power at all harmonics in the wide target output frequency range. In one or more embodiments, the output series matching circuit and / or the output series-parallel matching circuit can also comprise multiple capacitors and inductors to achieve output matching for the wide target output frequency range.

[0027] Further, the nonlinear transmission line circuit comprises a plurality of nonlinear transmission line units connected in series, and each nonlinear transmission line unit comprises a series inductor and a parallel variable capacitor connected in parallel to the series inductor. In some embodiments, the parallel variable capacitors in each nonlinear transmission line unit are all coupled to the corresponding series inductor with the same polarity, for example, all cathodes or all anodes. In some embodiments, the parallel variable capacitors in adjacent nonlinear transmission line units are coupled to the corresponding series inductor with different polarities, for example, the parallel variable capacitor in the former nonlinear transmission line unit is coupled to the series inductor with a cathode, and the parallel variable capacitor in the latter nonlinear transmission line unit is coupled to the series inductor with an anode.

[0028] In some embodiments, the parallel variable capacitor is a varactor diode, a Schottky diode, or any type of PN junction diode.

[0029] Further, from the signal input end to the signal output end, the inductance value of the series inductor of the former nonlinear transmission line unit is greater than or equal to the inductance value of the series inductor of the latter nonlinear transmission line unit; and / or the reference capacitance value of the parallel variable capacitor of the former nonlinear transmission line unit is greater than or equal to the reference capacitance value of the parallel variable capacitor of the latter nonlinear transmission line unit. The reference capacitance value of the variable capacitor is defined as the capacitance value of the variable capacitor under zero bias condition.

[0030] In the technical solution, the greater the time compression of the input signal during its propagation along the nonlinear transmission line circuit, the richer the high-frequency harmonic components contained in the input signal.

[0031] As a preferred embodiment of the nonlinear transmission line circuit in the application, when the number of stages of the nonlinear transmission line unit is increased to N+1 and the increase rate of harmonic power in the target output frequency range is less than a preset value, it is determined that the number of stages of the nonlinear transmission line unit is N, wherein N is a positive integer greater than or equal to 2. The measurement of the harmonic power includes, but is not limited to, summation, averaging or weighting of the power of multiple harmonics in the target input frequency range.

[0032] Generally, the increase of the number of stages of the nonlinear transmission line circuit is more conducive to the generation of high-frequency harmonic components, but the increase of the number of stages also brings more insertion loss. Therefore, the determination of the number of stages of the nonlinear transmission line circuit in the application effectively balances the benefits of the increase of the number of stages on the generation of high-frequency harmonic components and the loss caused by the increase of the number of stages, and is conducive to further improving the harmonic output power.

[0033] Specifically, after each increase of the number of stages of the nonlinear transmission line unit, the growth rate of the harmonic power in the target output frequency range compared to the harmonic power before the increase of the number of stages can be obtained. If the growth rate is less than a preset value, the number of stages before the increase is adopted. Otherwise, if the growth rate is greater than or equal to the preset value, it indicates that the current number of stages is effective, and the increase of the number of stages of the nonlinear transmission line unit can be continued until the growth rate is less than the preset value.

[0034] Further, the preset value of the growth rate is preferably 1% to 5%.

[0035] Compared with the prior art, the utility model has the following advantages and beneficial effects:

[0036] 1、 the utility model discloses a input series matching circuit is arranged in the front end of nonlinear transmission line circuit, can reduce the echo reflection that generates in the comb spectrum generator after inputting high -power signal in target input frequency range, makes when the frequency of high -power input signal is in target input frequency range, high -power input signal can as far as possible no -lossly enter nonlinear transmission line circuit, thereby effectively converts high -order harmonic output, improves the power conversion rate of high -power input signal;

[0037] 2、The utility model discloses a input series matching circuit is introduced, although the wider frequency bandwidth range of NLTL circuit is sacrificed, but in the narrower target input frequency range, the " input-output " power conversion efficiency of input high -power signal is improved, and the power conversion efficiency in target output frequency range is improved significantly.

[0038] 3、The utility model discloses the output matching circuit is connected in the rear end of nonlinear transmission line circuit, so that the target output frequency range is optimized and matched, and the output return loss is reduced, so that the harmonic in target output frequency range can be output better, and the harmonic output power is further improved.

[0039] 4、The utility model discloses the number of nonlinear transmission line units in NLTL circuit is determined according to the target output frequency range of output signal, and the influence of unit series on the benefit and loss of high -frequency harmonic component is balanced effectively, and it is favorable to further improve harmonic output power. BRIEF DESCRIPTION OF DRAWINGS

[0040] The drawings described herein are used to provide further understanding of the embodiments of the utility model, and constitute a part of this application, and do not constitute the limitation to the embodiments of the utility model.

[0041] Figure 1 It is the comb spectrum generator of the utility model specific embodiment and is provided with input series matching circuit in the front end of nonlinear transmission line circuit;

[0042] Figure 2 It is the nonlinear transmission line circuit in prior art;

[0043] Figure 3 It is the comb spectrum generator of the utility model specific embodiment and is provided with input series matching circuit and input parallel matching circuit in the front end of nonlinear transmission line circuit;

[0044] Figure 4 It is the comb spectrum generator of the utility model specific embodiment and is provided with input series matching circuit, input parallel matching circuit and output matching circuit;

[0045] Figure 5 It is the harmonic power test result of the output spectrum line of the comb spectrum generator of (a) not setting input series matching circuit, input parallel matching circuit, output matching circuit, (b) the harmonic power test result of the output spectrum line of the comb spectrum generator shown in embodiment 4. DETAILED DESCRIPTION

[0046] In the following description, specific details of the invention will be set forth to facilitate understanding of the invention. However, the invention may be practiced even without some or all of the specific details described. The embodiments of the invention described below may be incorporated into many different electrical components, circuits, devices, and systems. The structures and devices shown in the block diagrams of the accompanying drawings are used to illustrate exemplary embodiments of the invention, but are not intended to obscure the broad guidance of the invention. The connections between elements shown in the drawings are not limited to direct connections. Rather, the connections between elements can be modified, reconfigured, or otherwise altered through intermediate components.

[0047] In this invention, references to "one embodiment" or "a particular embodiment" indicate that a specific feature, structure, characteristic, or function related to the embodiment being discussed is included in at least one contemplated embodiment of the invention. Therefore, the phrase "in one embodiment" appearing in different places in the specification does not constitute multiple references to a single embodiment of the invention. Each reference or document mentioned in this patent document is incorporated herein by reference in its entirety. It should be noted that any examples provided herein are provided by way of illustration and are carried out under specific conditions using one or more specific embodiments; therefore, none of these examples should be used to limit the scope of disclosure of this patent document.

[0048] The terms "first," "second," etc., used in this invention (e.g., first capacitor, second capacitor, first inductor, second inductor, etc.) are merely for clarity of description and are not intended to restrict any order or emphasize importance. Furthermore, the term "connection" used in this invention, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

[0049]

Example 1

[0050] like Figure 1 The comb spectrum generator 20 shown includes a nonlinear transmission line circuit NLTL 22 connected between a signal input terminal RFin and a signal output terminal RFout, and an input power conversion efficiency matching circuit 21 connected between the signal input terminal and the nonlinear transmission line circuit. The input power conversion efficiency matching circuit 21 includes an input series matching circuit 211, which includes an inductor L4 connected to the signal input terminal, a first inductor L1 connected to the NLTL, and a first capacitor C1 connected between the two inductors.

[0051] In some embodiments, inductor L4 is the bonding wire equivalent inductance.

[0052] The input power conversion efficiency matching circuit matches the input high power signal in the target input frequency range, reduces the echo reflection generated inside the comb spectrum generator after the input high power signal in the target input frequency range, so that when the frequency of the high power input signal is in the target input frequency range, the high power input signal can enter the nonlinear transmission line circuit as much as possible without loss, thereby effectively converting into high harmonic output and improving the power conversion rate of the high power input signal.

[0053] In one or more embodiments, a certain specified frequency f0 of the target input frequency range is the input frequency of the input high power signal received by the signal input end. Wherein f0 is any frequency value that can be specified according to actual needs, for example, f0 is 850MHz, 1GHz or 2GHz. (f1, f2) is the target input frequency range containing the frequency point f0, and in some preferred embodiments, the f0, the lowest frequency f1 of the target input frequency range and the highest frequency f2 of the target input frequency range satisfy (f2-f1) / f0≤25%.

[0054] In some embodiments, when f0 is 1GHz, the first capacitor C1 in the series matching circuit 211 can be 15pF.

[0055] In one or more embodiments, the input series matching circuit 211 includes one or more inductors and capacitors to achieve power conversion efficiency matching for a specific frequency point or a specific narrowband frequency range.

[0056] In this embodiment, the NLTL 22 can adopt any existing nonlinear transmission line circuit. In one or more embodiments, the NLTL 22 adopts the periodic structure in patent CN115940885A. Specifically, as shown in Figure 2 The nonlinear transmission line circuit 310 includes a plurality of nonlinear transmission line units in series, such as 321, 322, etc., each unit including a series inductor L and a parallel variable capacitor D. As shown in Figure 3 The first segment 321 includes a first series inductor L1 and a first parallel variable capacitor D1 coupled to the first series inductor L1 at a first node B1; the second segment 322 includes a second series inductor L2 and a second parallel variable capacitor D2 coupled to the second series inductor L2 at a second node B2; and the Nth segment includes an Nth series inductor Ln and an Nth parallel variable capacitor Dn coupled to the Nth series inductor Ln at an Nth node Bn.

[0057] In some preferred embodiments, from the signal input terminal to the signal output terminal, the inductance value of the series inductor of the preceding nonlinear transmission line unit is greater than the inductance value of the series inductor of the following nonlinear transmission line unit; and / or the reference capacitance value of the parallel variable capacitor of the preceding nonlinear transmission line unit is greater than the reference capacitance value of the parallel variable capacitor of the following nonlinear transmission line unit. For example, the inductance value of the first series inductor L1 is greater than the inductance value of the second series inductor L2, and as another example, the reference capacitance value of the first parallel variable capacitor D1 is greater than the reference capacitance value of the second parallel variable capacitor D2.

[0058]

Example 2

[0059] Based on Example 1, such as Figure 3 The comb spectrum generator 40 shown includes a nonlinear transmission line circuit NLTL 42 connected between the signal input terminal RFin and the signal output terminal RFout. The NLTL 42 can be any nonlinear transmission circuit in the prior art. It also includes an input power conversion efficiency matching circuit 41 connected between the signal input terminal and the nonlinear transmission circuit. The input power conversion efficiency matching circuit 41 includes an input series matching circuit 411 and an input parallel matching circuit 412.

[0060] The input series matching circuit 411 includes a first inductor L1, an inductor L4, and a first capacitor C1. The inductor L4 is connected to the signal input terminal, the first end of the first capacitor C1 is connected to the inductor L4, the second end of the first capacitor C1 is connected to the first inductor L1, and the first inductor L1 is connected in series to the NLTL.

[0061] The input parallel matching circuit 412 includes a second capacitor C2, with one end of the second capacitor C2 connected to the input series matching circuit 411 and the other end of the second capacitor C2 grounded. In some preferred embodiments, the second capacitor C2 can be replaced by a variable capacitor, or a combination of a fixed capacitor and a variable capacitor.

[0062] In some embodiments, the input parallel matching circuit 412 may also be equipped with multiple capacitors to achieve power conversion efficiency matching for a specific frequency point or a specific narrowband frequency range.

[0063]

Example 3

[0064] Based on the above embodiments, such as Figure 4A comb spectrum generator 50 is shown, which includes a nonlinear transmission line circuit NLTL 52 connected between a signal input end RFin and a signal output end RFout, the NLTL 52 can adopt any nonlinear transmission line circuit in the prior art; and further includes an input power conversion efficiency matching circuit 51 connected between the signal input end and the nonlinear transmission circuit, the input power conversion efficiency matching circuit 51 includes an input series matching circuit 511 and an input parallel matching circuit 512.

[0065] The input series matching circuit 511 includes a first inductor L1, an inductor L4, and a first capacitor C1, wherein the inductor L4 is connected to the signal input end, the first end of the first capacitor C1 is connected to the inductor L4, the second end of the first capacitor C1 is connected to the first inductor L1, and the first inductor L1 is connected in series to the NLTL.

[0066] The input parallel matching circuit 512 includes a second capacitor C2, the first end of the second capacitor C2 is connected to the input series matching circuit 511, and the other end of the second capacitor C2 is grounded. In some preferred embodiments, the second capacitor C2 can be replaced by a variable capacitor, or a combination of a fixed capacitor and a variable capacitor.

[0067] An output matching circuit 53 is further provided between the nonlinear transmission line circuit and the signal output end, the output matching circuit 53 includes an output series matching circuit 531 and an output series matching circuit 532, and the output series matching circuit 531 and the output series matching circuit 532 constitute a band-pass filter network. The output series matching circuit 531 includes a third inductor L3 and a third capacitor C3 connected in series, one end of the third capacitor C3 is connected to the output end of the output series parallel matching circuit, the other end of the third capacitor C3 is connected to the third inductor L3, and the third inductor L3 is connected to the signal output end RFout, wherein the third inductor L3 is a bond wire equivalent inductor. In one or more embodiments, the positions of the third inductor L3 and the third capacitor C3 can be interchanged. The output series parallel matching circuit 532 includes a fourth inductor L2 and a fourth capacitor C4, the fourth inductor L2 is connected in series between the nonlinear transmission line circuit NLTL and the output series matching circuit 531, one end of the fourth capacitor C4 is connected in parallel between the fourth inductor L2 and the output series matching circuit, and the other end of the fourth capacitor C4 is grounded. In one or more embodiments, the fourth capacitor C4 can be a variable capacitor, such as a varactor diode, or a combination of a fixed capacitor and a variable capacitor.

[0068] In the embodiment, the output matching circuit 53 is used to ensure that the comb spectrum generator outputs in a wider target output frequency range, the target output frequency range falls within the passband range of the bandpass filter network, and all harmonics in the wider target output frequency range have higher output power. In one or more embodiments, the output series matching circuit and / or the output series-parallel matching circuit can also include multiple capacitors, inductors to achieve output matching for a wideband target output frequency range.

[0069] [Embodiment 4]

[0070] On the basis of the above-mentioned embodiments, the number of stages of the NLTL is further optimized, and the number of non-linear transmission line units in the NLTL circuit is determined according to the target output frequency range of the output signal.

[0071] Specifically, when the number of stages of the non-linear transmission line unit is increased to N+1, the increase rate of the harmonic power in the target output frequency range is less than a preset value, and the number of stages of the non-linear transmission line unit is N, where N is a positive integer greater than or equal to 2.

[0072] For example, when the number of stages of the non-linear transmission line unit is increased to 5, the harmonic power in the target output frequency range of the comb spectrum generator with the number of stages of 5 is obtained, and compared with the harmonic power when the number of stages is 4. If the growth rate is greater than or equal to the preset value, the number of stages of the non-linear transmission line unit can be increased to 6, and further judgment is made until the growth rate after the number of stages is increased is less than the preset value. By balancing the benefits of the increased number of stages on high-frequency harmonic components and the loss caused by the increased number of stages, the harmonic output power is further improved.

[0073] In some preferred embodiments, the preset value is 1% to 5%.

[0074] [Embodiment 5]

[0075] As Figure 5 (a) and Figure 5 (b) respectively show the comparison of the harmonic power test results of the output spectrum of the comb spectrum generator 310 based on the prior art and the comb spectrum generator in Embodiment 4 under the condition of a high-power signal with an input power of 18dBm when the input frequency is 1GHz. It can be seen from the comparison that the harmonic power of the output spectrum is greatly improved by using the scheme of the present application, especially in the target output frequency range of 8-20GHz, the output power is improved by 8-10dB.

[0076] The above embodiments describe the present application to make it clear and understandable, but are not intended to limit the present application to the disclosed precise forms. Various modifications are also possible within the scope and equivalent scope of the appended claims.

[0077] Those skilled in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the scope of the present application. All modifications, equivalents, combinations and alternatives falling within the true spirit and scope of the present application are therefore intended to be embraced by the following claims.

[0078] It should also be noted that the various claims recited below have one or more aspects, and are therefore interdependent. For example, in certain embodiments, the subject matter of one claim can be combined with the subject matter of another claim to create a new claim, or can be used in combination with an element or elements of another claim.

Claims

1. A comb spectrum generator comprising a nonlinear transmission line circuit connected between a signal input and a signal output, characterized in that, The input series matching circuit comprises at least one first inductor and at least one first capacitor connected in series with the first inductor.

2. A comb spectrum generator according to claim 1, characterized in that The input parallel matching circuit comprises at least one second capacitor.

3. A comb spectrum generator according to claim 2, wherein The input series matching circuit is configured to change the broadband matching performance of the nonlinear transmission line circuit, so that the input signal at the preset target input frequency point f0 or the input signal within the target input frequency range (f1, f2) containing the frequency point f0 has higher input power conversion efficiency at the target output frequency point or the target output frequency range than the nonlinear transmission line circuit without the input series matching circuit.

4. A comb spectrum generator according to claim 1 or 2, characterized in that The output matching circuit comprises an output series matching circuit and an output series-parallel matching circuit, one end of the output series-parallel matching circuit being connected between the nonlinear transmission line circuit and the output series matching circuit, and the other end of the output series-parallel matching circuit being grounded. The output series matching circuit comprises at least one third inductor and at least one third capacitor connected in series with the third inductor. The output series-parallel matching circuit comprises at least one fourth inductor and at least one fourth capacitor connected in parallel with the fourth inductor.

5. A comb spectrum generator according to claim 4, characterized in that The fourth capacitor is a variable capacitor.

6. A comb spectrum generator according to claim 4, wherein The nonlinear transmission line circuit comprises a plurality of nonlinear transmission line units connected in series, each nonlinear transmission line unit comprising a series inductor and a parallel variable capacitor connected in parallel with the series inductor.

7. A comb spectrum generator according to claim 6, characterized in that In the direction from the signal input end to the signal output end, the inductance value of the series inductor of a previous nonlinear transmission line unit is greater than or equal to the inductance value of the series inductor of a subsequent nonlinear transmission line unit, and / or the reference capacitance value of the parallel variable capacitor of the previous nonlinear transmission line unit is greater than or equal to the reference capacitance value of the parallel variable capacitor of the subsequent nonlinear transmission line unit.

8. A comb spectrum generator according to claim 6, wherein When the number of nonlinear transmission line units is increased to N+1, if the harmonic power increase rate within the target output frequency range is less than a preset value, it is determined that the number of nonlinear transmission line units is N, where N is a positive integer greater than or equal to 2.

9. A comb spectrum generator according to claim 8, characterized in that The preset value is 1% to 5%.

10. A comb spectrum generator according to claim 6, wherein The parallel variable capacitor is a varactor diode, a Schottky diode, or a PN junction diode.

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