A comb spectrum signal generator

Abstract

This invention relates to the field of signal source technology, and more particularly to a comb spectrum signal generator. The signal generator includes a housing, a cover plate, a circuit board, and a power supply circuit, a crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner disposed on the circuit board. The comb spectrum signal generator of this invention transmits a frequency signal through the crystal oscillator. The frequency conversion circuit converts the frequency signal transmitted by the crystal oscillator into multiple desired frequency signals for output. These multiple desired frequency signals are amplified by the amplifier circuit and filtered by the filter circuit before being combined into a single output signal by the combiner. The output signal is stable and powerful, with small power differences and good spectral consistency. It is also easy to debug and has low power consumption. Furthermore, the entire circuit board is housed in a sealed metal housing, providing good shielding and easy installation.

Description

Technical Field

[0001] This invention relates to the field of signal source technology, and in particular to a comb spectrum signal generator. Background Technology

[0002] A signal source, also called a signal generator, is a device that provides a specific frequency, waveform, and output power. It is used as a test signal source or excitation source when measuring the amplitude characteristics, frequency characteristics, transmission characteristics, and other electrical parameters of various telecommunications equipment and systems. Signal generators can be classified according to the type of output signal, such as radio frequency signal generators, scanning signal generators, frequency combiners, noise signal generators, and pulse signal generators. Existing traditional comb spectrum signal generators mostly use harmonic generators, resulting in poor frequency stability and significant differences in signal power across different spectrums.

[0003] In view of this, the industry urgently needs a comb spectrum signal generator. Summary of the Invention

[0004] This invention provides a comb-shaped spectrum signal generator to solve the technical problems of large differences in spectral signal power and poor frequency stability in existing signal generators in the background art.

[0005] This invention provides a comb spectrum signal generator, including a housing, a cover plate, a circuit board, and a power supply circuit, a crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner disposed on the circuit board;

[0006] A crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner are connected in sequence; the crystal oscillator is used to transmit frequency signals; the frequency conversion circuit is used to receive the frequency signals transmitted by the crystal oscillator and convert them into multiple channels of the desired set frequency signals;

[0007] The amplifier circuit is used to amplify multiple signals of the desired frequency; the filter circuit is used to filter the amplified signals of the desired frequency; the combiner is used to combine the filtered signals of the desired frequency into a single output signal.

[0008] The power supply circuit is connected to the crystal oscillator, frequency conversion circuit and amplifier circuit respectively, and is used to power the crystal oscillator, frequency conversion circuit and amplifier circuit.

[0009] The circuit board is installed inside the housing, and the cover plate closes the housing to form a sealed shielded space.

[0010] Furthermore, the number of amplifier circuits corresponds to the number of multiple frequency signals converted by the frequency conversion circuit. Multiple amplifier circuits are respectively set at the output terminal of the frequency conversion circuit, and each amplifier circuit amplifies the multiple frequency signals generated by the frequency conversion circuit.

[0011] Furthermore, the number of filter circuits corresponds to the number of amplifier circuits, with multiple filter circuits respectively set at the output terminals of multiple amplifier circuits; used for filtering the amplified multi-frequency signals.

[0012] Furthermore, the frequency conversion circuit includes a shaping circuit, a gating circuit, and a frequency divider circuit; the gating circuit and the frequency divider circuit are respectively connected in parallel to the output terminal of the shaping circuit, and the input terminal of the shaping circuit is connected to the output terminal of the crystal oscillator.

[0013] Furthermore, the shaping circuit includes a first resistor, a second resistor, and a first inverter; the first pin of the first inverter is connected to the output terminal of the power supply circuit, the second pin of the first inverter is connected to the first resistor and the second resistor connected in series, and the free end of the second resistor is connected to the output terminal of the power supply circuit; the input terminal of the first inverter is connected to the output terminal of the crystal oscillator, and the output terminal of the first inverter is connected to the gating circuit and the frequency divider circuit respectively.

[0014] Furthermore, the selection circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor; the first inductor and the second inductor are connected in series, the first capacitor is located at the free end of the first inductor, and the other end of the first capacitor is connected to the output terminal of the first inverter; the second capacitor is located at the free end of the second inductor, and the other end of the second capacitor serves as an output port; the third capacitor is located between the first inductor and the second inductor, and the other end of the third capacitor is grounded.

[0015] Furthermore, the frequency divider circuit includes multiple dual-channel counters and multiple dual-channel calculators arranged in parallel and connected in sequence;

[0016] The dual-channel counter includes a first channel counter and a second channel counter designed in parallel. The input terminal of the first channel counter is connected to the output terminal of the first inverter. The output terminal of the first channel counter is used as one signal output, and the output terminal of the first channel counter is connected to the input terminal of the second channel counter as the signal input of the second channel counter. The output terminal of the second channel counter is used as another signal output, and the output of the second channel counter is also used as the input of the next dual-channel counter.

[0017] Furthermore, the frequency conversion circuit also includes a DC blocking capacitor, which is used to block DC output of the signal; the DC blocking capacitor includes: a first DC blocking capacitor, a second DC blocking capacitor, a third DC blocking capacitor, and a fourth DC blocking capacitor; the first DC blocking capacitor is located between the input terminal of the first inverter and the output terminal of the crystal oscillator; the second DC blocking capacitor is connected in parallel with the gating circuit and the frequency divider circuit to the output terminal of the first inverter; the third DC blocking capacitor is located between the output terminal of the first inverter and the input terminal of the first bidirectional counter; the fourth DC blocking capacitor is located at the output terminal of the bidirectional counter.

[0018] Furthermore, the amplifier circuit includes a second inverter, a third resistor, a fourth resistor, a fourth capacitor, and a fifth capacitor;

[0019] One end of the third resistor is connected to the output of the power supply circuit, and the other end of the third resistor is connected to the first pin of the second inverter. One end of the fourth resistor is connected to the input of the second inverter, and the other end of the fourth resistor is connected to the output of the second inverter. The second pin of the second inverter is grounded. One end of the fourth capacitor is connected to the output of the frequency conversion circuit, and the other end of the fourth capacitor is connected in parallel with the fourth resistor to the input of the second inverter. One end of the fifth capacitor is grounded, and the other end of the fifth capacitor is connected in parallel with the third resistor to the second pin of the second inverter.

[0020] Furthermore, the filter circuit includes a third inductor, a fourth inductor, a sixth capacitor, a seventh capacitor, and an eighth capacitor; the third inductor and the fourth inductor are connected in series, the sixth capacitor is located at the free end of the third inductor, and the other end of the sixth capacitor is connected to the output terminal of the frequency divider circuit; the seventh capacitor is located at the free end of the fourth inductor, and the other end of the seventh capacitor serves as the output port; the eighth capacitor is located between the third inductor and the fourth inductor, and the other end of the eighth capacitor is grounded.

[0021] Beneficial effects

[0022] The comb-shaped spectrum signal generator provided by this invention transmits a frequency signal through a crystal oscillator. A frequency conversion circuit converts the frequency signal transmitted by the crystal oscillator into multiple desired frequency signals for output. These multiple desired frequency signals are amplified by an amplifier circuit and filtered by a filter circuit before being combined into a single output signal by a combiner. The output signal is stable and has high power; at the same time, the output signal power difference is small, the spectral consistency is good, and it is easy to debug and has low power consumption. In addition, the entire circuit board is housed in a sealed metal casing, which facilitates installation and provides good shielding. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the comb spectrum signal generator provided in an embodiment of the present invention;

[0024] Figure 2 yes Figure 1 A block diagram showing the connection structure of various components in a circuit board.

[0025] Figure 3 yes Figure 2 Block diagram of the circuit board for signal processing;

[0026] Figure 4 yes Figure 2 A schematic diagram of the frequency conversion circuit structure in the diagram;

[0027] Figure 5 yes Figure 2 A schematic diagram of the amplifier circuit structure in the image;

[0028] Figure 6 yes Figure 2 A schematic diagram of the filter circuit structure in the image;

[0029] Figure 7 This is a schematic diagram of the output spectrum of the comb spectrum signal generator according to an embodiment of the present invention;

[0030] In the picture:

[0031] 1. Cover plate, 2. Circuit board, 3. Housing, 4. Through-core capacitor, 5. SMA connector, 6. Power supply circuit, 7. Crystal oscillator, 8. Frequency conversion circuit, 9. Amplifier circuit, 10. Filter circuit, 11. Combiner, S1, First inverter, S2, Second inverter, N1, First dual-channel counter, N2, Second dual-channel counter. Detailed Implementation

[0032] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0033] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0034] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0035] See Figures 1 to 7 The present invention provides a comb spectrum signal generator, including a housing, a cover plate, a circuit board, and a power supply circuit, a crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner disposed on the circuit board;

[0036] A crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner are connected in sequence; the crystal oscillator is used to transmit frequency signals; the frequency conversion circuit is used to receive the frequency signals transmitted by the crystal oscillator and convert them into multiple channels of the desired set frequency signals;

[0037] The amplifier circuit is used to amplify multiple signals of the desired frequency; the filter circuit is used to filter the amplified signals of the desired frequency; the combiner is used to combine the filtered signals of the desired frequency into a single output signal.

[0038] The power supply circuit is connected to the crystal oscillator, frequency conversion circuit and amplifier circuit respectively, to supply power to the crystal oscillator, frequency conversion circuit and amplifier circuit; the circuit board is installed in the housing, and the cover plate closes the housing to form a sealed shielded space.

[0039] The comb-shaped spectrum signal generator provided by this invention transmits a frequency signal through a crystal oscillator. A frequency conversion circuit converts the frequency signal transmitted by the crystal oscillator into multiple desired frequency signals for output. These multiple desired frequency signals are amplified by an amplifier circuit and filtered by a filter circuit before being combined into a single output signal by a combiner. The output signal is stable and has high power; at the same time, the output signal power difference is small, the spectral consistency is good, and it is easy to debug and has low power consumption. In addition, the entire circuit board is housed in a sealed metal casing, which facilitates installation and provides good shielding.

[0040] See Figures 1 to 4 The signal generator of this application includes a metal cover plate 1, a circuit board 2, a metal housing 3, a through-core capacitor 4, and an SMA connector 5. The circuit board 2 is installed inside the metal housing 3, and the cover plate 1 and the housing 3 form a sealed cavity, constituting a shielded space.

[0041] A through-core capacitor is provided on one side of the housing. The through-core capacitor is connected to the input terminal of the power supply circuit. The external power supply provides power to the product through the through-core capacitor 4. An SMA connector is provided on the other side of the housing. The SMA connector is connected to the output terminal of the combiner. The output signal is output through the SMA connector 5.

[0042] The circuit board includes a power supply circuit 6, a crystal oscillator 7, a frequency conversion circuit 8, an amplifier circuit 9, a filter circuit 10, and a combiner 11. The power supply circuit 6 primarily regulates and filters the input voltage before supplying power to the crystal oscillator, the frequency conversion circuit, and the amplifier circuit 9. The crystal oscillator outputs a 10MHz frequency signal, which, after passing through the frequency conversion circuit, generates five signals with frequencies of 30MHz, 10MHz, 1MHz, 100kHz, and 10kHz respectively. These five signals are then amplified and filtered by the amplifier circuit and finally combined by the combiner to form a single output signal.

[0043] The frequency conversion circuit includes a shaping circuit, a gating circuit, and a frequency divider circuit; the gating circuit and the frequency divider circuit are connected in parallel to the output terminal of the shaping circuit, and the input terminal of the shaping circuit is connected to the output terminal of the crystal oscillator.

[0044] The shaping circuit includes a first resistor, a second resistor, and a first inverter S1; the first pin of the first inverter is connected to the output terminal of the power supply circuit, the second pin of the first inverter is connected to the first and second resistors connected in series, and the free end of the second resistor is connected to the output terminal of the power supply circuit; the input terminal of the first inverter is connected to the output terminal of the crystal oscillator, and the output terminal of the first inverter is connected to the gating circuit and the frequency divider circuit respectively.

[0045] The selection circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor; the first inductor and the second inductor are connected in series, the first capacitor is located at the free end of the first inductor, and the other end of the first capacitor is connected to the output terminal of the first inverter; the second capacitor is located at the free end of the second inductor, and the other end of the second capacitor serves as the output port; the third capacitor is located between the first inductor and the second inductor, and the other end of the third capacitor is grounded.

[0046] The frequency divider circuit includes multiple dual-channel counters arranged in parallel and connected sequentially. The dual-channel counters include a first channel counter and a second channel counter designed in parallel. The input terminal of the first channel counter is connected to the output terminal of the first inverter. The output terminal of the first channel counter serves as one signal output and is also connected to the input terminal of the second channel counter, serving as the signal input of the second channel counter. The output terminal of the second channel counter serves as another signal output and also serves as the input of the next dual-channel counter.

[0047] In this embodiment, the frequency divider circuit includes a first dual-channel counter N1 and a second dual-channel counter N2. The first dual-channel counter and the second dual-channel counter are arranged in parallel and connected in sequence.

[0048] Specifically, the 10MHz signal generated by the crystal oscillator is shaped into a square wave signal by a shaping circuit. This square wave signal is then divided into three paths: one path filters to select a 30MHz signal, another path directly outputs a 10MHz signal, and the third path enters a frequency divider circuit. N1 is the first dual-channel counter, and N2 is the second dual-channel counter; both N1 and N2 are preferably dual-channel decimal counters, capable of frequency division by 10. The first counter in N1 converts the 10MHz signal into a 1MHz signal output, and this 1MHz output serves as the input to the second counter, resulting in a 100kHz signal after division. Similarly, the 100kHz signal enters the first counter in N2 as input, resulting in a 10kHz signal after division; the second counter in N2 is left floating. It is important to note that when N1 and N2 perform a tenfold frequency division, dividing by 5 first, then by 2, yields a signal with greater power and a better waveform.

[0049] Preferably, the frequency conversion circuit further includes a DC blocking capacitor, which is used to block DC output of the signal. The DC blocking capacitor includes: a first DC blocking capacitor, a second DC blocking capacitor, a third DC blocking capacitor, and a fourth DC blocking capacitor. The first DC blocking capacitor is located between the input terminal of the first inverter and the output terminal of the crystal oscillator. The second DC blocking capacitor is connected in parallel with the gating circuit and the frequency divider circuit at the output terminal of the first inverter. The third DC blocking capacitor is located between the output terminal of the first inverter and the input terminal of the first bidirectional counter. The fourth DC blocking capacitor is located at the output terminal of the bidirectional counter. The DC blocking capacitor effectively isolates the DC current contained in the signal, improving the stability of the signal.

[0050] See Figure 5 The amplifier circuit includes a second inverter, a third resistor, a fourth resistor, a fourth capacitor, and a fifth capacitor;

[0051] One end of the third resistor is connected to the output of the power supply circuit, and the other end of the third resistor is connected to the first pin of the second inverter. One end of the fourth resistor is connected to the input of the second inverter, and the other end of the fourth resistor is connected to the output of the second inverter. The second pin of the second inverter is grounded. One end of the fourth capacitor is connected to the output of the frequency conversion circuit, and the other end of the fourth capacitor is connected in parallel with the fourth resistor to the input of the second inverter. One end of the fifth capacitor is grounded, and the other end of the fifth capacitor is connected in parallel with the third resistor to the second pin of the second inverter.

[0052] Specifically, the second inverter uses a 74HC1G04 inverter, R3 is a step-down resistor, and adjusting the resistance value can change the signal output power; R4 is a signal negative feedback resistor, which can also provide DC bias voltage to the input terminal. C4 is an input coupling capacitor, and C5 is a power supply filter capacitor.

[0053] See Figure 6The filter circuit includes a third inductor, a fourth inductor, a sixth capacitor, a seventh capacitor, and an eighth capacitor. The third and fourth inductors are connected in series. The sixth capacitor is located at the free end of the third inductor, and its other end is connected to the output of the frequency divider circuit. The seventh capacitor is located at the free end of the fourth inductor, and its other end serves as the output port. The eighth capacitor is located between the third and fourth inductors, and its other end is grounded. In this embodiment, the filter circuit is a T-type LC filter circuit. The square wave signal output from the amplifier circuit is transformed into a sine wave signal after being filtered by the T-type LC filter circuit. Through simulation calculations of the various parameters, the signal attenuation can be less than 2dB, and the harmonic suppression can be better than 30dBc.

[0054] Figure 7 The diagram shows the output spectrum of the comb-shaped spectrum signal source. As can be seen from the diagram, the output amplitude of each signal of the product meets the requirement of 11±2dBm. The product is applied to the test antenna system and performs well.

[0055] The comb-shaped spectrum signal generator of this invention has a product volume of 90mm×70mm×20mm consisting of a metal shell and a cover plate; it is compact in size.

[0056] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. The present invention is not limited to the specific steps and structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0057] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art without departing from the scope of the invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of this application should be included within the scope of the claims of this application.

Claims

1. A comb-shaped spectrum signal generator, characterized in that, Includes housing, cover plate, circuit board, and power supply circuit, crystal oscillator, frequency conversion circuit, amplifier circuit, filter circuit and combiner mounted on the circuit board; A crystal oscillator, a frequency conversion circuit, an amplifier circuit, a filter circuit, and a combiner are connected in sequence; the crystal oscillator is used to transmit frequency signals; the frequency conversion circuit is used to receive the frequency signals transmitted by the crystal oscillator and convert them into multiple channels of the desired set frequency signals; The amplifier circuit is used to amplify multiple signals of the desired frequency; the filter circuit is used to filter the amplified signals of the desired frequency; the combiner is used to combine the filtered signals of the desired frequency into a single output signal. The power supply circuit is connected to the crystal oscillator, frequency conversion circuit and amplifier circuit respectively, and is used to power the crystal oscillator, frequency conversion circuit and amplifier circuit. The circuit board is installed inside the housing, and the cover plate closes the housing to form a sealed shielded space.

2. The comb spectrum signal generator according to claim 1, characterized in that, The number of amplifier circuits corresponds to the number of multiple frequency signals converted by the frequency conversion circuit. Multiple amplifier circuits are respectively set at the output terminal of the frequency conversion circuit, and each amplifier circuit amplifies the multiple frequency signals generated by the frequency conversion circuit.

3. The comb spectrum signal generator according to claim 2, characterized in that, The number of filter circuits corresponds to the number of amplifier circuits; multiple filter circuits are respectively set at the output terminals of multiple amplifier circuits to filter the amplified multi-frequency signals.

4. The comb spectrum signal generator according to any one of claims 1-3, characterized in that, The frequency conversion circuit includes a shaping circuit, a gating circuit, and a frequency divider circuit; the gating circuit and the frequency divider circuit are connected in parallel to the output terminal of the shaping circuit, and the input terminal of the shaping circuit is connected to the output terminal of the crystal oscillator.

5. The comb spectrum signal generator according to claim 4, characterized in that, The shaping circuit includes a first resistor, a second resistor, and a first inverter; the first pin of the first inverter is connected to the output of the power supply circuit, the second pin of the first inverter is connected to the first and second resistors connected in series, and the free end of the second resistor is connected to the output of the power supply circuit; the input of the first inverter is connected to the output of the crystal oscillator, and the output of the first inverter is connected to the gating circuit and the frequency divider circuit respectively.

6. The comb spectrum signal generator according to claim 5, characterized in that, The selection circuit includes a first inductor, a second inductor, a first capacitor, a second capacitor, and a third capacitor; the first inductor and the second inductor are connected in series, the first capacitor is located at the free end of the first inductor, and the other end of the first capacitor is connected to the output terminal of the first inverter; the second capacitor is located at the free end of the second inductor, and the other end of the second capacitor serves as the output port; the third capacitor is located between the first inductor and the second inductor, and the other end of the third capacitor is grounded.

7. The comb spectrum signal generator according to claim 6, characterized in that, The frequency divider circuit includes multiple dual-channel counters and multiple dual-channel calculators arranged in parallel and connected in sequence; The dual-channel counter includes a first channel counter and a second channel counter designed in parallel. The input terminal of the first channel counter is connected to the output terminal of the first inverter. The output terminal of the first channel counter is used as one signal output, and the output terminal of the first channel counter is connected to the input terminal of the second channel counter as the signal input of the second channel counter. The output terminal of the second channel counter is used as another signal output, and the output of the second channel counter is also used as the input of the next dual-channel counter.

8. The comb spectrum signal generator according to claim 7, characterized in that, The frequency conversion circuit also includes a DC blocking capacitor, which is used to block DC output of the signal. The DC blocking capacitor includes: a first DC blocking capacitor, a second DC blocking capacitor, a third DC blocking capacitor, and a fourth DC blocking capacitor. The first DC blocking capacitor is located between the input terminal of the first inverter and the output terminal of the crystal oscillator. The second DC blocking capacitor is connected in parallel with the gating circuit and the frequency divider circuit at the output terminal of the first inverter. The third DC blocking capacitor is located between the output terminal of the first inverter and the input terminal of the first bidirectional counter. The fourth DC blocking capacitor is located at the output terminal of the bidirectional counter.

9. The comb spectrum signal generator according to claim 7, characterized in that, The amplifier circuit includes a second inverter, a third resistor, a fourth resistor, a fourth capacitor, and a fifth capacitor; One end of the third resistor is connected to the output of the power supply circuit, and the other end of the third resistor is connected to the first pin of the second inverter. One end of the fourth resistor is connected to the input of the second inverter, and the other end of the fourth resistor is connected to the output of the second inverter. The second pin of the second inverter is grounded. One end of the fourth capacitor is connected to the output of the frequency conversion circuit, and the other end of the fourth capacitor is connected in parallel with the fourth resistor to the input of the second inverter. One end of the fifth capacitor is grounded, and the other end of the fifth capacitor is connected in parallel with the third resistor to the second pin of the second inverter.

10. The comb spectrum signal generator according to claim 8, characterized in that, The filter circuit includes a third inductor, a fourth inductor, a sixth capacitor, a seventh capacitor, and an eighth capacitor. The third and fourth inductors are connected in series. The sixth capacitor is located at the free end of the third inductor, and the other end of the sixth capacitor is connected to the output terminal of the frequency divider circuit. The seventh capacitor is located at the free end of the fourth inductor, and the other end of the seventh capacitor serves as the output port. The eighth capacitor is located between the third and fourth inductors, and the other end of the eighth capacitor is grounded.

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