A broadband nonlinear transmission line comb spectrum generator chip

Abstract

The present invention relates to a high-power broadband nonlinear transmission line comb generator chip. The comb generator chip is composed of 40 levels of nonlinear transmission line units in periodic cascade, wherein each nonlinear transmission line unit is composed of a high-resistance microstrip line and three base-emitter short-circuited transistors. A certain degree of waveform compression can be achieved after the radio frequency signal passes through each level of nonlinear transmission unit. After passing through a certain number of nonlinear transmission units, a DC-100GHz series of harmonic pulse signals can be obtained at the chip output port, and then the required harmonic components in the solitary wave can be filtered out through a frequency selection network to realize a high-order frequency multiplication function. The present invention has a wide operating frequency, and reduces the energy reflection of harmonics by bending and folding the routing, thereby achieving higher harmonic power output and smaller chip size, filling the gap in domestic high-order frequency multiplication comb generator chips.

Description

Technical Field

[0001] The invention discloses a broadband nonlinear transmission line comb spectrum generator chip, belonging to the technical field of radio frequency microwave integrated circuits of microelectronics and solid electronics. Background Art

[0002] In recent years, with the rapid application of wireless communication systems in various high-end equipment such as radar and guidance, high-power, broadband modulated signals are more conducive to the transmission of information. Nonlinear transmission lines are widely used in high-speed sampling oscilloscopes, time domain reflectometers, comb generators and frequency synthesizers. Nonlinear transmission line comb generators generally use high-order pulse compression technology to achieve high-order frequency multiplication of low-frequency signals.

[0003] Traditional frequency multipliers can generally achieve low-order frequency multiplication. For high-order frequency multiplication, the circuit design is complex, the chip area is large, and the wafer production cost is high. Summary of the invention

[0004] The present invention proposes a broadband nonlinear transmission line comb spectrum generator chip with a wide operating frequency range, high harmonic output power, high frequency multiplication number and small chip size. The purpose of the present invention is to address the defects of the prior art, based on the theory of nonlinear transmission lines and soliton waves, and utilize the soliton wave decomposition characteristics on the nonlinear transmission line to achieve a high-order comb spectrum, and provide a broadband nonlinear transmission line comb spectrum generator with a wide operating frequency range, high harmonic output power, high frequency multiplication number and small chip size.

[0005] The technical solution of the present invention is a broadband nonlinear transmission line comb generator chip, which is composed of a periodic cascade of multiple nonlinear transmission line units, each of which includes a high-resistance microstrip line and three transistors, and the base and emitter of the transistors are short-circuited.

[0006] The chip layout adopts curved and folded routing.

[0007] The chip includes 40 levels of nonlinear transmission units.

[0008] In the 40-level nonlinear transmission unit, the first high-resistance microstrip line TL1, the first base-emitter short-circuited transistor D1, the second base-emitter short-circuited transistor D2, and the third base-emitter short-circuited transistor D3 constitute a first nonlinear transmission line unit NLTL1, wherein one end of the first high-resistance microstrip line TL1 is used as the input end of the comb generator, and the other end is connected to the collector of the first base-emitter short-circuited transistor D1, and the base of the first base-emitter short-circuited transistor D1 is connected to the collector of the second base-emitter short-circuited transistor D2. The base of the second base-emitter shorting transistor D2 is connected to the collector of the third base-emitter shorting transistor D3, and the base of the third base-emitter shorting transistor D3 is grounded; the second high-resistance microstrip line TL2, the fourth base-emitter shorting transistor D4, the fifth base-emitter shorting transistor D5, and the sixth base-emitter shorting transistor D6 constitute a second nonlinear transmission line unit NLTL2, wherein one end of the second high-resistance microstrip line TL2 is connected to the collector of the first base-emitter shorting transistor D1, and the other end is connected to the collector of the first base-emitter shorting transistor D2. The collectors of the four base-emitter shorting transistors D4 are connected, the base of the fourth base-emitter shorting transistor D4 is connected to the collector of the fifth base-emitter shorting transistor D5, the base of the fifth base-emitter shorting transistor D5 is connected to the collector of the sixth base-emitter shorting transistor D6, and the base of the sixth base-emitter shorting transistor D6 is grounded; the third high-resistance microstrip line TL3, the seventh base-emitter shorting transistor D7, the eighth base-emitter shorting transistor D8, and the ninth base-emitter shorting transistor D9 constitute a third nonlinear transmission line unit NLTL3, wherein one end of the third high-resistance microstrip line TL3 is connected to the collector of the fourth base-emitter shorting transistor D4, and the other end is connected to the collector of the seventh base-emitter shorting transistor D7, the base of the seventh base-emitter shorting transistor D7 is connected to the collector of the eighth base-emitter shorting transistor D8, the base of the eighth base-emitter shorting transistor D8 is connected to the collector of the ninth base-emitter shorting transistor D9, and the base of the ninth base-emitter shorting transistor D9 is grounded;By analogy, the 40th high-resistance microstrip line TL40, the 118th base-emitter shorting transistor D118, the 119th base-emitter shorting transistor D119, and the 120th base-emitter shorting transistor D120 constitute the 40th nonlinear transmission line unit NLTL40, wherein one end of the 40th high-resistance microstrip line TL40 is connected to the collector of the 115th base-emitter shorting transistor D115, and the other end is connected to the collector of the 118th base-emitter shorting transistor D118, the base of the 118th base-emitter shorting transistor D118 is connected to the collector of the 119th base-emitter shorting transistor D119, the base of the 119th base-emitter shorting transistor D119 is connected to the collector of the 120th base-emitter shorting transistor D120, and the base of the 120th base-emitter shorting transistor D120 is grounded. ;

[0009] The collector of the one hundred and eighteenth base-emitter short-circuited transistor D118 serves as the output terminal of the comb generator.

[0010] The beneficial effects of the present invention are as follows: the circuit topology is simple, the operating frequency is wide, and the energy reflection of harmonics is reduced by bending and folding the wiring, thereby achieving higher harmonic power output and smaller chip size, filling the gap in domestic high-order frequency comb generator chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is the circuit structure diagram of broadband nonlinear transmission line comb generator.

[0012] Figure 2 is a circuit layout of a broadband nonlinear transmission line comb generator in an embodiment of the present invention;

[0013] Figure 3 This is a harmonic output power spectrum diagram when the input signal is 1 GHz and the power is 23 dBm in an embodiment of the present invention;

[0014] Figure 4 The waveform curves of input and output signals when the input signal is 1 GHz and the power is 23 dBm in the embodiment;

[0015] Figure 5 This is the harmonic output power spectrum diagram when the input signal is 5GHz and the power is 23dBm in the embodiment;

[0016] Figure 6 The waveform curves of input and output signals when the input signal is 5 GHz and the power is 23 dBm in the embodiment;

[0017] Figure 7This is the harmonic output power spectrum diagram when the input signal is 10GHz and the power is 23dBm in the embodiment;

[0018] Figure 8 This is the input and output signal waveform curve when the input signal is 10 GHz and the power is 23 dBm in the embodiment.

[0019] In the figure, TL1-TL40 are high-resistance microstrip lines, D1-120 are emitter short-circuited transistors, NLTL140 is a nonlinear transmission line unit, 1 is the signal input port, and 2 is the signal output port. DETAILED DESCRIPTION

[0020] A high-power broadband nonlinear transmission line comb generator chip. The comb generator chip is composed of 40 levels of nonlinear transmission line units in periodic cascade, wherein each nonlinear transmission line unit is composed of a high-resistance microstrip line and three base-emitter short-circuited transistors. The high-resistance microstrip line and the strong nonlinear varactor diode are periodically cascaded to form a nonlinear transmission line that can generate solitary waves, and a series of pulse signals are obtained by using the decomposition characteristics of the soliton wave on the nonlinear transmission line.

[0021] Furthermore, the input signal obtains a high-order pulse signal after passing through the nonlinear transmission line.

[0022] As a specific example, the comb generator chip is composed of forty levels of nonlinear transmission line units periodically cascaded, including the first to fortieth high-resistance microstrip lines, the first base-emitter short-circuited transistor to the one hundred and twentieth base-emitter short-circuited transistor.

[0023] The first high-resistance microstrip line, the first base-emitter shorting transistor, the second base-emitter shorting transistor, and the third base-emitter shorting transistor constitute a first nonlinear transmission line unit. One end of the first high-resistance microstrip line serves as the input end of the comb generator, and the other end is connected to the collector of the first base-emitter shorting transistor, the base of the first base-emitter shorting transistor is connected to the collector of the second base-emitter shorting transistor, the base of the second base-emitter shorting transistor is connected to the collector of the third base-emitter shorting transistor, and the base of the third base-emitter shorting transistor is grounded. The second high-resistance microstrip line, the fourth base-emitter shorting transistor, the fifth base-emitter shorting transistor, and the sixth base-emitter shorting transistor constitute a second nonlinear transmission line unit. Among them, one end of the second high-resistance microstrip line is connected to the collector of the first base-emitter shorting transistor, and the other end is connected to the collector of the fourth base-emitter shorting transistor, the base of the fourth base-emitter shorting transistor is connected to the collector of the fifth base-emitter shorting transistor, the base of the fifth base-emitter shorting transistor is connected to the collector of the sixth base-emitter shorting transistor, and the base of the sixth base-emitter shorting transistor is grounded. The third high-resistance microstrip line, the seventh base-emitter shorting transistor, the eighth base-emitter shorting transistor, and the ninth base-emitter shorting transistor constitute a third nonlinear transmission line unit. Among them, one end of the third high-resistance microstrip line is connected to the collector of the fourth base-emitter shorting transistor, and the other end is connected to the collector of the seventh base-emitter shorting transistor, the base of the seventh base-emitter shorting transistor is connected to the collector of the eighth base-emitter shorting transistor, the base of the eighth base-emitter shorting transistor is connected to the collector of the ninth base-emitter shorting transistor, and the base of the ninth base-emitter shorting transistor is grounded. Similarly, the 40th high-resistance microstrip line, the 118th base-emitter shorting transistor, the 119th base-emitter shorting transistor, and the 120th base-emitter shorting transistor constitute the 40th nonlinear transmission line unit. Among them, one end of the fortieth high-resistance microstrip line is connected to the collector of the fifteenth base-emitter shorting transistor, and the other end is connected to the collector of the eighteenth base-emitter shorting transistor, the base of the eighteenth base-emitter shorting transistor is connected to the collector of the nineteenth base-emitter shorting transistor, the base of the nineteenth base-emitter shorting transistor is connected to the collector of the twentieth base-emitter shorting transistor, and the base of the twentieth base-emitter shorting transistor is grounded.

[0024] The collector of the one hundred and eighteenth base-emitter short-circuited transistor (D118) of the comb generator serves as the output terminal of the comb generator.

[0025] Furthermore, in the nonlinear transmission line comb generator, the variable capacitor formed by the short-circuited base and emitter of the transistor has strong nonlinearity and fast charging and discharging of the capacitor. The comb generator output waveform is closer to a rectangular pulse and has better nonlinearity, which is conducive to generating high-power harmonic signals. In theory, increasing the number of nonlinear transmission line units can effectively increase the harmonic output power, but when a certain number is reached, the loss and distributed parameter influence of the nonlinear transmission line will be greater than its nonlinearity. The comb generator maximizes the harmonic output power by reasonably selecting transistors, the number of nonlinear transmission line units and the signal routing method.

[0026] The technical solution of the present invention is further described below in conjunction with the accompanying drawings

[0027] As attached Figure 1 As shown, a broadband nonlinear transmission line comb spectrum generator includes a high-resistance microstrip line and a strong nonlinear varactor diode composed of a base-emitter short-circuited transistor.

[0028] The nonlinear transmission line comb generator chip realizes high-order compression of the waveform after the input signal passes through the multi-stage nonlinear transmission line unit, and can obtain a high-order pulse signal, and then the required pulse components in the solitary wave can be filtered out through a frequency selection network with a high rectangular coefficient.

[0029] As a specific example, the comb generator chip is composed of forty levels of nonlinear transmission line units periodically cascaded, including the first to fortieth high-resistance microstrip lines TL1~TL40, the first base-emitter short-circuited transistor to the one hundred and twentieth base-emitter short-circuited transistor D1~D120.

[0030] The first high-resistance microstrip line TL1, the first base-emitter shorting transistor D1, the second base-emitter shorting transistor D2, and the third base-emitter shorting transistor D3 constitute a first nonlinear transmission line unit NLTL1. Among them, one end of the first high-resistance microstrip line TL1 serves as the input end of the comb generator, and the other end is connected to the collector of the first base-emitter shorting transistor D1, the base of the first base-emitter shorting transistor D1 is connected to the collector of the second base-emitter shorting transistor D2, the base of the second base-emitter shorting transistor D2 is connected to the collector of the third base-emitter shorting transistor D3, and the base of the third base-emitter shorting transistor D3 is grounded. The second high-resistance microstrip line TL2, the fourth base-emitter shorting transistor D4, the fifth base-emitter shorting transistor D5, and the sixth base-emitter shorting transistor D6 constitute a second nonlinear transmission line unit NLTL2. Among them, one end of the second high-resistance microstrip line TL2 is connected to the collector of the first base-emitter shorting transistor D1, and the other end is connected to the collector of the fourth base-emitter shorting transistor D4, the base of the fourth base-emitter shorting transistor D4 is connected to the collector of the fifth base-emitter shorting transistor D5, the base of the fifth base-emitter shorting transistor D5 is connected to the collector of the sixth base-emitter shorting transistor D6, and the base of the sixth base-emitter shorting transistor D6 is grounded. The third high-resistance microstrip line TL3, the seventh base-emitter shorting transistor D7, the eighth base-emitter shorting transistor D8, and the ninth base-emitter shorting transistor D9 constitute a third nonlinear transmission line unit NLTL3. Among them, one end of the third high-resistance microstrip line TL3 is connected to the collector of the fourth base-emitter shorting transistor D4, and the other end is connected to the collector of the seventh base-emitter shorting transistor D7, the base of the seventh base-emitter shorting transistor D7 is connected to the collector of the eighth base-emitter shorting transistor D8, the base of the eighth base-emitter shorting transistor D8 is connected to the collector of the ninth base-emitter shorting transistor D9, and the base of the ninth base-emitter shorting transistor D9 is grounded. By analogy, the fortieth high-resistance microstrip line TL40, the one hundred and eighteenth base-emitter shorting transistor D118, the one hundred and nineteenth base-emitter shorting transistor D119, and the one hundred and twentieth base-emitter shorting transistor D120 constitute the fortieth nonlinear transmission line unit NLTL40.Among them, one end of the fortieth high-resistance microstrip line TL40 is connected to the collector of the one-hundred-and-fifteenth base-emitter short-circuited transistor D115, and the other end is connected to the collector of the one-hundred-and-eighteenth base-emitter short-circuited transistor D118, the base of the one-hundred-and-eighteenth base-emitter short-circuited transistor D118 is connected to the collector of the one-hundred-and-nineteenth base-emitter short-circuited transistor D119, the base of the one-hundred-and-nineteenth base-emitter short-circuited transistor D119 is connected to the collector of the one-hundred-and-twentieth base-emitter short-circuited transistor D120, and the base of the one-hundred-and-twentieth base-emitter short-circuited transistor D120 is grounded.

[0031] Furthermore, the collector of the one hundred and eighteenth base-emitter short-circuited transistor D118 serves as the output terminal of the comb generator.

[0032] Example 1

[0033] The circuit structure block diagram of the broadband nonlinear transmission line comb generator of this embodiment is as follows: Figure 1 shown.

[0034] like Figure 1 As shown, a broadband nonlinear comb generator chip of the present invention is composed of 40 levels of nonlinear transmission line units cascaded, and each nonlinear unit is composed of a high-resistance microstrip line and three base-emitter short-circuited transistors. In order to ensure that the nonlinear transmission line has strong nonlinearity, the variable capacitance of the three base-emitter short-circuited transistors must be much larger than the parasitic capacitance of the microstrip line, and the characteristic impedance of the microstrip line should be greater than 75Ω.

[0035] The present invention selects the transistor base-emitter short circuit, and the slope of its CV curve is the largest, the capacitor charges and discharges faster, the comb generator output waveform is closer to a rectangular pulse, has better nonlinearity, and is conducive to generating a high-power pulse signal. In addition, the larger the transistor size, the greater the harmonic output power, but when the input frequency increases, the parasitic parameters of the varactor will become more significant, resulting in a lower harmonic output power.

[0036] In order to further improve the harmonic output power and frequency doubling, the comb generator must make the rising / falling slope of the output waveform large enough, and realize high-order pulse compression by cascading a higher Bragg cutoff frequency transmission line. In theory, the input signal can obtain an ideal rectangular wave after passing through a sufficient number of nonlinear units, but in fact, when the number of nonlinear units increases to a certain number, the loss and distribution parameters of the nonlinear transmission line will have a greater impact than its nonlinearity, resulting in the harmonic output power not continuing to increase. Therefore, selecting the optimal number of nonlinear units is one of the key difficulties of the present invention.

[0037] The circuit layout of the broadband nonlinear transmission line comb generator of the embodiment of the present invention is as follows: Figure 2As shown in FIG. 1 , the layout mainly consists of 0.7 μm InP HBT transistors, microstrip lines, ground holes, and RF ports. The RF signal enters from the signal input port 1, passes through 40 nonlinear transmission line units, and is output from the signal output port 2.

[0038] Figure 3 to Figure 8 They are respectively the measured spectrum curve and the input and output signal waveform curves of the broadband nonlinear transmission line comb spectrum generator of the present invention. Figure 3 It is the harmonic output power spectrum line when the input signal frequency is 1GHz and the power is 23dBm. Figure 4 Input and output signal waveform curves under this working condition; Figure 5 It is the harmonic output power spectrum line under the input signal frequency of 5GHz and power of 23dBm. Figure 6 Input and output signal waveform curves under this working condition; Figure 7 It is the harmonic output power spectrum line under the input signal frequency of 10GHz and power of 23dBm. Figure 8 The waveform curves of input and output signals under this working condition are shown in the figure. It can be seen from the time domain waveform that the waveform of the input sinusoidal signal is compressed after passing through the nonlinear transmission line, and rich high-order harmonic components can be generated in the frequency domain. This comb generator has a wide operating frequency range, covering DC-100GHz. When a 1GHz sinusoidal signal is injected, the 60th harmonic output can reach more than -36dBm, achieving higher frequency multiplication and harmonic output power than similar designs at home and abroad.

Claims

1. A broadband nonlinear transmission line comb generator chip, characterized in that It is composed of a periodic cascade of multiple nonlinear transmission line units, each of which includes a high-resistance microstrip line and three transistors, and the base and emitter of the transistors are short-circuited; The chip layout adopts curved and folded routing; The chip includes 40 levels of nonlinear transmission units; In the 40-level nonlinear transmission unit, a first high-resistance microstrip line (TL1), a first base-emitter short-circuited transistor (D1), a second base-emitter short-circuited transistor (D2), and a third base-emitter short-circuited transistor (D3) constitute a first nonlinear transmission line unit (NLTL1), wherein one end of the first high-resistance microstrip line (TL1) serves as an input end of the comb generator, and the other end is connected to the collector of the first base-emitter short-circuited transistor (D1), and the base of the first base-emitter short-circuited transistor (D1) is connected to the collector of the second base-emitter short-circuited transistor (D2). , the base of the second base-emitter shorting transistor (D2) is connected to the collector of the third base-emitter shorting transistor (D3), and the base of the third base-emitter shorting transistor (D3) is grounded; the second high-resistance microstrip line (TL2), the fourth base-emitter shorting transistor (D4), the fifth base-emitter shorting transistor (D5), and the sixth base-emitter shorting transistor (D6) constitute a second nonlinear transmission line unit (NLTL2), wherein one end of the second high-resistance microstrip line (TL2) is connected to the collector of the first base-emitter shorting transistor (D1), and the other end is connected to the collector of the first base-emitter shorting transistor (D2). The collectors of the four base-emitter shorting transistors (D4) are connected, the base of the fourth base-emitter shorting transistor (D4) is connected to the collector of the fifth base-emitter shorting transistor (D5), the base of the fifth base-emitter shorting transistor (D5) is connected to the collector of the sixth base-emitter shorting transistor (D6), and the base of the sixth base-emitter shorting transistor (D6) is grounded; the third high-resistance microstrip line (TL3), the seventh base-emitter shorting transistor (D7), the eighth base-emitter shorting transistor (D8), and the ninth base-emitter shorting transistor (D9) form a A third nonlinear transmission line unit (NLTL3) is formed, wherein one end of the third high-resistance microstrip line (TL3) is connected to the collector of the fourth base-emitter shorting transistor (D4), and the other end is connected to the collector of the seventh base-emitter shorting transistor (D7), the base of the seventh base-emitter shorting transistor (D7) is connected to the collector of the eighth base-emitter shorting transistor (D8), the base of the eighth base-emitter shorting transistor (D8) is connected to the collector of the ninth base-emitter shorting transistor (D9), and the base of the ninth base-emitter shorting transistor (D9) is grounded;By analogy, the fortieth high-resistance microstrip line (TL40), the one hundred and eighteenth base-emitter shorting transistor (D118), the one hundred and nineteenth base-emitter shorting transistor (D119), and the one hundred and twentieth base-emitter shorting transistor (D120) constitute a fortieth nonlinear transmission line unit (NLTL40), wherein one end of the fortieth high-resistance microstrip line (TL40) is connected to the collector of the one hundred and fifteenth base-emitter shorting transistor (D115), and the other end is connected to the collector of the one hundred and fifteenth base-emitter shorting transistor (D115). The collector of the one hundred and eighteenth base-emitter shorting transistor (D118) is connected, the base of the one hundred and eighteenth base-emitter shorting transistor (D118) is connected to the collector of the one hundred and nineteenth base-emitter shorting transistor (D119), the base of the one hundred and nineteenth base-emitter shorting transistor (D119) is connected to the collector of the one hundred and twentieth base-emitter shorting transistor (D120), and the base of the one hundred and twentieth base-emitter shorting transistor (D120) is grounded. ; 2. A broadband nonlinear transmission line comb generator chip according to claim 1, characterized in that The collector of the one hundred and eighteenth base-emitter shorting transistor (D118) serves as the output terminal of the comb generator.

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