Multiplexer, spectrum analyzer, signal analyzer, signal generator, and multiplexer control method using the same

Abstract

To provide a multiplexer, a spectrum analyzer, a signal analyzer, a signal generator, and a multiplexer control method using the same, which can easily change a passband without switching filters and has a simple and inexpensive structure and is capable of supporting high-precision measurement, analysis, and testing of high-frequency signals.SOLUTION: A multiplexer 10 includes two BPFs 20a1 connected in parallel between hybrids 18a1 and 19a1, and a BPF 20b1 connected to a port P4 of the hybrid 18a1 and having a passband adjacent to the passband of the BPF 20a1. The multiplexer 10 also includes passband varying means 40a, 40b, and 40c for varying the passbands of the BPFs 20a1 and the hybrid 18a1 within a band range in which overlapping bands are formed within a predetermined frequency range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a multiplexer based on a circuit structure in which a pair of filters are arranged between hybrids, the filters having a function of varying the passband, a spectrum analyzer, a signal analyzer, a signal generator using the same, and a method for controlling a multiplexer. [Background technology]

[0002] A filter for extracting signal components in a desired passband from an input signal is a waveguide filter that uses a waveguide formed with a waveguide that introduces and passes signal components.

[0003] As an example of a waveguide filter, an inductive iris-coupled waveguide filter in which multiple cavity resonators are coupled via multiple irises has been known (for example, Patent Document 1, etc.). This inductive iris-coupled waveguide filter has a structure in which a first inductive iris and a second inductive iris are arranged on the input side and the output side, respectively.

[0004] Also known is a filter bank structure in which a filter block in which a plurality of waveguides are formed using waveguides is mechanically moved to a position where both ends of a specified waveguide are connected to a waveguide in a first fixed waveguide block and a waveguide in a second fixed waveguide block (for example, Patent Document 2, etc.). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-184831 [Patent Document 2] Japanese Patent Application Publication No. 2019-87862 Summary of the Invention [Problem to be solved by the invention]

[0006] Spectrum analyzers are known that can use a waveguide filter such as that described in Patent Document 1 or a waveguide block switching mechanism such as that described in Patent Document 2 in a filter section that extracts signals of multiple frequency bands from a signal under test.

[0007] With today's rapid progress in communication technologies related to 5G and various wireless communications, spectrum analyzers are being required to accurately detect the influence of spurious components in higher frequency bands, such as millimeter waves (200 GHz to 300 GHz), in order to achieve even more advanced communication technologies in the future. Similar demands are also growing for signal analyzers that can use the above-mentioned waveguide filters or waveguide block switching mechanisms in the filter section, and for signal generators that generate test signals for receiver sensitivity tests of devices under test (DUTs).

[0008] To meet the above-mentioned requirements, some conventional spectrum analyzers have adopted a filter bank as the filter section, for example, having a configuration as shown in Fig. 17. In Fig. 17, each of filters 91a, 91b, and 91c has two hybrids 93 and 94 (hybrids 93a1 and 94a1, 93b1 and 94b1, and 93c1 and 94c1), and has a pair of filters 95a1, 95b1, and 95c1 disposed between the two hybrids 93 and 94, respectively. Hybrids 93 and 94 that use branch-line couplers (BLC) are called BLC filter banks.

[0009] In a spectrum analyzer using a BLC filter bank, there is no need to mechanically switch between filters with different passbands; signals in the desired band can be obtained simply by extracting the signals that pass through filters 95a1, 95b1, and 95c1 of each filter 91a, 91b, and 91c.

[0010] However, the BLC filter bank was originally not designed to allow the passbands of adjacent filters 95a1, 95b1, and 95c1 to overlap, so in order to ensure overlap and prevent signal measurement (or analysis or DUT testing) from being impossible, it was necessary to provide multiple BLC filter banks as shown in Fig. 17 and switch between groups of BLC filter banks.

[0011] For this reason, in conventional spectrum analyzers, signal analyzers, and signal generators that use a BLC filter bank such as the one shown in Figure 17, the configuration for switching the filter section and the switching control are complicated, making it extremely difficult to measure, analyze, or test frequency components in higher frequency bands such as millimeter waves with a simple and inexpensive configuration.

[0012] The present invention has been made to solve the above-mentioned problems of the related art, and has an object to provide a multiplexer that can easily change the passband without switching filters, has a simple and inexpensive structure, and is capable of high-precision measurement, analysis, and testing of high-frequency signals, as well as a spectrum analyzer, signal analyzer, signal generator, and multiplexer control method that use the same. [Means for solving the problem]

[0013] In order to solve the above problems, a multiplexer according to claim 1 of the present invention comprises a first hybrid (18a1) and a second hybrid (19a1) each having a port P1 (Input), a port P2 (Through), a port P3 (Couple), and a port P4 (Isolated), and each of the first hybrid and the second hybrid is configured with a circuit network for dividing or combining signals, and two filters having substantially the same characteristics connected between the first hybrid and the second hybrid. The input side of one of the filters having a first passband variable means (40a) is connected to the port P2 of the first hybrid and the output side is connected to the port 1 of the second hybrid, and the input side of the other filter having a second passband variable means (40b) is connected to the port P3 of the first hybrid and the output side is connected to the port 4 of the second hybrid.a first filter (20a1) and a second filter (20b1) connected to the port P4 of the first hybrid and having a passband adjacent to the passband of the first filter, wherein an input signal from the port P1 of the first hybrid is distributed to two of the first filters, and if the input signal is within the respective passbands, the signal passes through the first filter, is combined in the second hybrid and is output from the port P3 of the second hybrid, while if the input signal is outside the passband of the first filter, the signal is reflected, is combined in the first hybrid and is output from the port P4 to the second filter, and the passbands of the first filter and the second filter are Through a continuous band overlapping bands are formed like The present invention is characterized by having variable passband variable means (40a, 40b, 40c).

[0014] With this configuration, the multiplexer according to claim 1 of the present invention can easily and continuously vary the passband without switching filters by varying the passbands of the first filter and the second filter using the passband varying means, and can accommodate high-precision measurement, analysis, and testing of high-frequency signals with a simple and inexpensive structure.

[0015] Furthermore, a multiplexer according to claim 2 of the present invention may be configured such that a basic unit has a configuration including the first hybrid, the second hybrid, the first filter, and the second filter, and a plurality of the basic units are sequentially connected so that the port P1 of the first hybrid of the subsequent basic unit is connected to the port P4 of the first hybrid of the previous basic unit or the port P3 of the second hybrid of the previous basic unit, and the first filter and the second filter of the previous and subsequent basic units are configured to vary the passbands so that overlapping bands are formed through successive bands.

[0016] With this configuration, the multiplexer according to claim 2 of the present invention can construct a filter structure capable of supporting an extended desired passband with a simple structure by combining multiple basic units, and can also facilitate high-precision measurement, analysis, and testing of high-frequency signals.

[0017] In addition, in the multiplexer according to claim 3 of the present invention, the first filter and the second filter of each of the basic units may have a configuration of one type of filter selected from the group consisting of a band-pass filter, a high-pass filter, and a low-pass filter, or a combination of two or more types of filters.

[0018] With this configuration, the multiplexer according to claim 3 of the present invention can easily realize a filter structure with desired specifications by combining a hybrid with one or more of a band-pass filter, a high-pass filter, and a low-pass filter.

[0019] In a multiplexer according to claim 4 of the present invention, the first filter and the second filter are configured by waveguide filters (20), and the waveguide filters each have a rectangular parallelepiped shape and include a first waveguide section (31a) and a second waveguide section (31b) each having a groove (35a, 35b) to be a waveguide (35) formed on one side surface (32a, 32b) in the longitudinal direction from one end (33) to the other end (34) in the longitudinal direction, and The waveguide may be formed by the groove in a state where the second waveguide sections are disposed opposite each other with the one side surfaces facing each other, and the passband of the waveguide may be changed depending on the gap between the one side surface of the first waveguide section and the one side surface of the second waveguide section (30), and a gap adjustment mechanism (43, 43A) that constitutes the passband varying means and varies the gap in the waveguide section so as to set a desired passband.

[0020] With this configuration, the multiplexer according to claim 4 of the present invention can easily realize a passband variable means by using a gap adjustment mechanism that adjusts the gap between the first waveguide portion and the second waveguide portion of the waveguide filter.

[0021] Furthermore, in the multiplexer according to claim 5 of the present invention, the gap adjustment mechanism (43A) may have a configuration including a first stage member (52a) on which the first waveguide portion is placed, a second stage member (52b) on which the second waveguide portion is placed so as to face the first waveguide portion, and driving means (50a, 50b) that drives the first stage member and the second stage member to be movable symmetrically with respect to a plane of symmetry so as to change the gap between the first waveguide portion and the second waveguide portion.

[0022] With this configuration, the multiplexer of claim 5 of the present invention can easily and continuously vary the gap between the first waveguide portion and the second waveguide portion by using the driving means to drive the first stage member and the second stage member so that they move symmetrically with respect to the symmetry plane, and can improve the filter characteristics when the passband is varied.

[0023] In the multiplexer according to claim 6 of the present invention, the waveguide section The frequency characteristic is such that the pass band decreases as the gap between the first waveguide portion (31a) and the second waveguide portion (31b) increases, The signals to be measured within the predetermined frequency range are input to the waveguide, and the signals overlap each other. one The gap in the frequency band Depending on the size of The frequency component of any one of the bands that matches the pass band may be output.

[0024] With this configuration, the multiplexer according to claim 6 of the present invention can set a desired passband from among a plurality of passbands within a predetermined frequency range according to the gap by varying the gap using the gap adjustment mechanism.

[0025] In order to solve the above problem, a spectrum analyzer according to claim 7 of the present invention provides a signal to be measured in a predetermined frequency range together with a local signal output from a local signal generator (112) to a mixer (111); The mixer mixes the signal under test and the local signal.A spectrum analyzer (1) having a frequency conversion unit (100) having a filter (113) for extracting a signal of a predetermined intermediate frequency band from a mixed output, and a detector (120) for detecting the signal of the intermediate frequency band, and for determining the spectrum characteristics of the signal under measurement by changing the frequency of the local signal according to a frequency to be analyzed, further comprising: request The present invention is characterized in that the multiplexer (10A) according to claim 1 is provided, and a passband variable control means (151) is provided for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the frequencies to be analyzed is set, and the frequency components corresponding to one frequency band of the frequencies to be analyzed are measured through the multiplexer.

[0026] With this configuration, the spectrum analyzer according to claim 7 of the present invention can easily and continuously vary the passband without switching filters by varying the passbands of the first filter and the second filter using the passband varying means, thereby enabling high-frequency signals to be measured with high precision using a simple and inexpensive structure.

[0027] Furthermore, a spectrum analyzer according to claim 8 of the present invention may have a basic unit having a configuration including the first hybrid, the second hybrid, the first filter, and the second filter, and the multiplexer (10A) is formed by combining a plurality of the basic units (10-11, 10-12), and the first filter and the second filter of each of the basic units may be configured to vary the passbands so that overlapping bands are formed through consecutive bands.

[0028] With this configuration, the spectrum analyzer according to claim 8 of the present invention can construct a multiplexer filter structure that can accommodate a desired extended passband by combining multiple basic units with a simple structure, and can easily accommodate high-precision measurement, analysis, and testing of high-frequency signals.

[0029] In order to solve the above problem, a signal analyzer according to claim 9 of the present invention is a signal analyzer that generates a signal to be measured in a predetermined frequency range from a local signal generator (112 D ) and the local signal output from the mixer (111D), The mixer mixes the signal under test and the local signal. A signal analyzer (2) includes a frequency conversion unit (100D) having a filter (113D) for extracting a signal of a predetermined intermediate frequency band from a mixed output, and a signal analysis unit (153D) for converting the signal of the intermediate frequency band into a digital signal by an ADC (125) and then analyzing the waveform of the digital signal, and the signal analyzer (2) changes the frequency of the local signal according to a frequency to be analyzed and analyzes the waveform of the signal under measurement, the signal analyzer (2) comprising: request The present invention is characterized in that the multiplexer (10A) according to claim 1 is provided, and a passband variable control means (151D) is provided for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the frequencies to be analyzed is set, and a signal of a frequency component corresponding to one frequency band of the frequencies to be analyzed is analyzed through the multiplexer.

[0030] With this configuration, the signal analyzer according to claim 9 of the present invention can easily and continuously vary the passband without switching filters by varying the passbands of the first filter and the second filter using the passband varying means, thereby enabling high-precision analysis of high-frequency signals with a simple and inexpensive structure.

[0031] In order to solve the above problem, a signal generator according to claim 10 of the present invention has a frequency conversion unit (100E) that provides a test signal in an intermediate frequency band output from a signal generation unit (130) to a mixer (111E) together with a local signal output from a local signal generator (112E) to convert the signal into a signal in a predetermined frequency range, changes the frequency of the local signal according to a test frequency for testing a device under test (DUT), and sends out the signal after frequency conversion by the frequency conversion unit as the test signal for the device under test, wherein the signal after frequency conversion is input to a stage subsequent to the frequency conversion unit. requestThe present invention is characterized in that the multiplexer (10E) according to claim 1 is provided, and a passband variable control means (151E) is provided for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the frequencies to be tested is set, and the test signal having a frequency component corresponding to one frequency band of the frequencies to be tested that passes through the multiplexer is sent out.

[0032] With this configuration, the signal generator according to claim 10 of the present invention can easily and continuously vary the passband without switching filters by varying the passbands of the first filter and the second filter using the passband varying means, and can handle high-precision DUT testing of high-frequency signals with a simple and inexpensive structure.

[0033] In order to solve the above problem, a multiplexer control method according to claim 11 of the present invention is a multiplexer control method in a spectrum analyzer, a signal analyzer, or a signal generator that uses the multiplexer (10) according to claim 1, characterized in that it includes a setting step (S1, S11) of setting an analysis target frequency or a test target frequency, a passband variable control step (S3, S13) of driving and controlling the passband variable means so that the passbands to be selected for the first filter and the second filter are set based on the set analysis target frequency or the test target frequency, and a step (S4, S14) of extracting frequency components corresponding to the analysis target frequency or the test target frequency that pass through the first filter and the second filter having the passbands set by the passband variable means.

[0034] With this configuration, the multiplexer control method according to claim 11 of the present invention can be applied to a spectrum analyzer, a signal analyzer, or a signal generator, and by varying the passbands of the first filter and the second filter using the passband varying means, the passbands can be easily and continuously varied without switching filters, making it possible to perform high-precision measurement, analysis, and testing of high-frequency signals with a simple and inexpensive structure. [Effects of the Invention]

[0035] The present invention provides a multiplexer that can easily change the passband without switching filters, has a simple and inexpensive structure, and is capable of high-precision measurement, analysis, and testing of high-frequency signals, as well as a spectrum analyzer, signal analyzer, signal generator, and multiplexer control method that use the same. [Brief explanation of the drawings]

[0036] [Figure 1] FIG. 1 is a configuration diagram of a basic unit of a multiplexer according to the present invention. [Figure 2] 2 is a schematic diagram showing the distribution of frequency bands that can be extracted by a multiplexer having the basic unit structure shown in FIG. 1. FIG. [Figure 3] FIG. 2 is an exploded perspective view of a waveguide filter constituting a filter of a multiplexer having the basic unit structure shown in FIG. [Figure 4] 4A and 4B are plan views showing the configuration of the inner surface side of the first waveguide section and the second waveguide section that constitute the waveguide filter in FIG. 3, where (a) shows the first waveguide section and (b) shows the second waveguide section. [Figure 5] 4A and 4B are external views of the waveguide filter in FIG. 3, in which (a) shows a view from the side, (b), (c), and (d) show views from the front when the gap between the first waveguide portion and the second waveguide portion is G0, when the gap is G1, and when the gap is G2, respectively, and (e) shows the configuration of a gap adjustment portion according to a modified example of the gap adjustment portion in FIG. 1. [Figure 6]2 is a diagram showing an example of the configuration of a multiplexer according to the present invention using the basic unit shown in FIG. 1. FIG. [Figure 7] 1. FIG. 4 is a diagram showing another example of the configuration of a multiplexer according to the present invention using the basic unit shown in FIG. [Figure 8] 1. FIG. 4 is a diagram showing yet another example of the configuration of a multiplexer according to the present invention using the basic unit shown in FIG. [Figure 9] 9 is a diagram showing the configuration of a multiplexer according to one embodiment of the present invention, other than the configurations shown in FIGS. 6 to 8, which uses a plurality of basic units shown in FIG. 1. FIG. [Figure 10] 10 is a schematic diagram showing a distribution of passbands based on passband variable control in a passband variable filter in a multiplexer according to an embodiment of the present invention. FIG. [Figure 11] FIG. 1 is a diagram showing a general configuration of a spectrum analyzer using a multiplexer according to an embodiment of the present invention. [Figure 12] 4 is a flowchart showing a signal measurement control operation of a spectrum analyzer using a multiplexer according to an embodiment of the present invention. [Figure 13] FIG. 1 is a diagram showing a general configuration of a signal analyzer using a multiplexer according to an embodiment of the present invention. [Figure 14] 1 is a diagram showing a general configuration of a signal generating device using a multiplexer according to an embodiment of the present invention; [Figure 15] 1 is a configuration diagram of a multiplexer in a signal generating device using a multiplexer according to an embodiment of the present invention. [Figure 16] 5 is a flowchart showing a signal transmission control operation in a signal generating device using a multiplexer according to an embodiment of the present invention. [Figure 17] FIG. 1 is a diagram illustrating the configuration of a BLC filter bank used in a conventional spectrum analyzer. DETAILED DESCRIPTION OF THE INVENTION

[0037] Hereinafter, embodiments of a multiplexer according to the present invention, a spectrum analyzer, a signal analyzer, a signal generator, and a method for controlling a multiplexer using the multiplexer will be described.

[0038] (overview) The multiplexer 10 according to the present invention has a port P1 (Input), a port P2 (Through), a port P3 (Couple), and a port P4 (Isolated), and is configured using a hybrid consisting of a circuit network that distributes or combines signals, and a filter, to input a signal within a predetermined frequency range, and extract and output only signals with frequency components in a desired frequency band while suppressing unnecessary radio waves, i.e., spurious waves, contained in the input signal. The hybrid may be, for example, a branch line coupler, and the filter may be, for example, a band-pass filter (BPF), a high-pass filter (HPF), or a low-pass filter (LPF).

[0039] FIG. 1 shows the basic unit configuration of a multiplexer 10 according to the present invention. As shown in FIG. 1, the multiplexer 10 according to the present invention includes an input-side hybrid 18a1 having ports P1, P2, P3, and P4; an output-side hybrid 19a1 having the same structure; a BPF 20a1 consisting of two filters with substantially identical characteristics connected in parallel between the hybrids 18a1 and 19a1; and a BPF 20b1 connected to port P4 of the input-side hybrid 18a1. The BPFs 20a1 and 20b1 have passbands set to the frequency bands f1 and f2, respectively. The hybrids 18a1 and 19a1 constitute the first and second hybrids of the present invention, respectively. The BPFs 20a1 and 20b constitute the first and second filters of the present invention, respectively.

[0040] The multiplexer 10 having the above-described basic unit structure is configured so that a signal to be measured in a predetermined frequency range is input to the port P1 of the input-side hybrid 18a1. The predetermined frequency component is, for example, the sub-terahertz range of 100 GHz or higher but lower than 1 THz.

[0041] In the multiplexer 10 according to the present invention, a signal input from port P1 of the input-side hybrid 18a1 is output from ports P2 and P3 and distributed to two BPFs 20a1. The distributed signals are equal in power and 90° out of phase. If the distributed (input) signal is in the passband f1 of the BPF 20a1, it passes through each BPF 20a1 and is input to ports P1 and P4 of the output-side hybrid 19a1 with a 90° phase shift. The two signals are combined in the output-side hybrid 19a1, but the signals output from port P2 have a total phase shift of 180°, so they cancel each other out. On the other hand, the signals output from port P3 are in phase with each other, so they constructively combine and ideally would be output with the same power as the input. A termination resistor is connected to port P2 of the hybrid 19a1. This is to prevent the remaining signals from reflecting and causing adverse effects due to the non-ideal system.

[0042] On the other hand, if the signal input from port P1 of input hybrid 18a1 is a signal outside the passband f1 of BPF 20a1, for example, a signal in frequency band f2, it is reflected by BPF 20a1, passes through input hybrid 18a1 in the opposite direction from the input (synthesized), and is output to port P4, and then input to BPF 20b1. Here, since the input signal is a signal in the passband f2 of BPF 20b1, the input signal passes through BPF 20b1 and is output from its output terminal. In this way, multiplexer 10 having a basic unit structure is configured to extract signals of frequency components in the passbands f1 and f2 set for BPFs 20a1 and 20b1.

[0043] In a multiplexer 10 having the basic unit structure shown in FIG. 1, BPFs 20a1 and 20b1 have passband variable means 40a, 40b, and 40c that vary the passbands f1 and f2. The passband variable means can be realized by a gap adjuster 40 and a gap adjustment mechanism 43 (see FIG. 3) or a gap adjuster 40A and a gap adjustment mechanism 43A (see FIG. 5(a)), which will be described later. As a result, in a situation where signals of frequency bands f1 and f2 that do not overlap each other are mixed and input, as shown in FIG. 2, the multiplexer 10 having the basic unit structure can perform flexible passband operation by using the passband variable means 40a, 40b, and 40c to variably set the frequency band from f1 to slightly exceeding f2 as the passband for BPF 20a1, and the frequency band from f2 to slightly exceeding f3 as the passband (a passband having overlapping bands) for BPF 20b1.

[0044] As the BPFs 20a1, 20b1 having the passband varying means 40a, 40b, 40c in the multiplexer 10 having the basic unit structure according to the present invention, for example, a waveguide filter 20 having the configuration shown in Figures 3 to 5 can be used. The waveguide filter 20 will be described in detail later.

[0045] The multiplexer 10 according to the present invention has a basic unit structure in which BPFs 20a1 and 20b1 each having a passband variable means 40a, 40b, and 40c are arranged between an input-side hybrid 18a1 and an output-side hybrid 19a1. The multiplexer 10 can be used, for example, in a spectrum analyzer (see FIG. 11) that measures the distribution (spectrum) of frequency components contained in a high-frequency signal, a signal analyzer (see FIG. 13) that analyzes the waveforms of the frequency components, and a front-end circuit 101 of a signal generator (see FIG. 14) that generates a test signal for testing the receiving sensitivity of a DUT.

[0046] In a configuration in which the multiplexer 10 according to the present invention is provided in the front-end circuit 101 (see FIGS. 11, 13, and 14) of a spectrum analyzer, a signal analyzer, or a signal generator, the passband can be easily varied without switching between multiple filters using switches or the like by utilizing the passband variable function provided by the passband variable means 40a, 40b, and 40c provided in the multiplexer 10, and high-precision measurement, analysis, and DUT testing of high-frequency signals can be achieved with a simple and inexpensive structure.

[0047] In the following, we will explain in order the following: an embodiment (see Figures 3 to 5) of a variable passband filter (i.e., a waveguide filter 20 having variable passband means 40a, 40b, and 40c) provided in a multiplexer 10 configured using the above-mentioned basic units; various configuration examples (see Figures 6 to 8) of a multiplexer 10A that uses a combination of basic units; an embodiment of the multiplexer 10A (see Figures 9 and 10); an embodiment of a spectrum analyzer 1 that uses the multiplexer 10A (see Figures 11 and 12); an embodiment of a signal analyzer 2 that uses the multiplexer 10A (see Figure 13); and an embodiment of a signal generating device 3 that uses the multiplexer 10A as a multiplexer 10E (see Figures 14 to 16).

[0048] (Variable passband filter provided in multiplexer 10) The multiplexer 10 according to the present invention has the structure of the basic unit shown in Fig. 1, and is configured by disposing variable passband filters such as BPFs 20a1 and 20b1 between the input-side hybrid 18a1 and the output-side hybrid 19a1. The variable passband filters can be realized, for example, by a waveguide filter 20.

[0049] The configuration of the waveguide filter 20 provided in the multiplexer 10 as a variable passband filter will be described with reference to Figs. 3 to 5. Fig. 3 is an exploded perspective view of the waveguide filter 20 as a variable passband filter. Fig. 4 is a plan view showing the configuration of the inner surfaces of the first waveguide section 31a and the second waveguide section 31b that constitute the waveguide filter 20 in Fig. 3, where (a) shows the first waveguide section 31a and (b) shows the second waveguide section 31b. The first waveguide section 31a and the second waveguide section 31b respectively constitute the first waveguide section and the second waveguide section of the present invention.

[0050] As shown in FIG. 3, the waveguide filter 20 (corresponding to BPFs 20a1 and 20b1 in FIG. 1) included in the multiplexer 10 includes a waveguide section 30 and a gap adjuster 40. The waveguide section 30 has an overall rectangular parallelepiped shape that is elongated in one direction (the Y direction) and is configured by combining a first waveguide section 31a and a second waveguide section 31b, each of which has an identical shape. The waveguide section 30 has a structure that complies with a rectangular waveguide standard, such as WR3 or WR3.4. The WR3 or WR3.4 standard specifies the following conditions: a cutoff frequency (center frequency in the BPF) of 173.5 GHz, a frequency range of 220 to 325 GHz, a frequency band in the J band, and an inner diameter of 0.864 × 0.432 mm.

[0051] The first waveguide section 31a and the second waveguide section 31b have structures as shown in Figures 4(a) and 4(b), respectively. As shown in Figure 4(a), the first waveguide section 31a has a rectangular parallelepiped shape that divides the rectangular parallelepiped structure of the waveguide section 30 in approximately half in the longitudinal direction (Y direction). A groove 35a that will become a waveguide 35 is formed on one side surface 32a facing the other, second waveguide section 31b, from one end 33 to the other end 34 in the longitudinal direction. In a structure in which the first waveguide section 31a and the second waveguide section 31b are arranged with the one side surface 32a, 32b facing each other, the one side surface 32a of the first waveguide section 31a and the one side surface 32b of the second waveguide section 31b (see Figure 4(b)) form a plane of symmetry (magnetic wall) when there is no gap G, and the center of both forms the plane of symmetry when there is gap G.

[0052] In the first waveguide section 31a, the groove 35a is a rectangular cross-sectional groove formed by carving an appropriate depth in the X direction and an appropriate height h1 in the Z direction into the surface of one side surface 32a. The groove 35a has a uniform depth and height in the inner central portion of the first waveguide section 31a. Meanwhile, the groove 35a in this example has a tapered shape in which the height gradually increases from one end (the left end in the drawing) of the inner central portion of the first waveguide section 31a to just before the one end 33, and also from the other end (the right end in the drawing) of the inner central portion to just before the other end 34. In FIG. 4, the length of the tapered portion 35a1 of the first waveguide section 31a having the above-described tapered shape is indicated by l1.

[0053] In the first waveguide section 31a, in a part of the inner central part of the groove section 35a, a plurality of stub grooves 36 are formed as branch grooves having a predetermined length (stub height h2) along the Y direction and a predetermined length (stub length l2) in the Z direction (short side direction), at predetermined intervals corresponding to the cavity length l3 in the Y direction.

[0054] In a waveguide structure, if the propagation direction of the electromagnetic wave is called the "length," the longer side of the waveguide cross section is called the "width," and the shorter side of the waveguide cross section is called the "height," then the cavities and stubs in the first waveguide section 31a and the second waveguide section 31b shown in Fig. 4 are called differently. In the first waveguide section 31a and the second waveguide section 31b shown in Fig. 4, the propagation direction for the cavity is the Y direction, and the length, width, and height are the Y direction, X direction, and Z direction, respectively, while the propagation direction for the stub is the Z direction, and the length, width, and height are the Z direction, X direction, and Y direction, respectively.

[0055] The number of stub grooves 36 formed in the groove portion 35a of the first waveguide portion 31a can be any number, and the stub length l2, stub height h2, and spacing (cavity length l3) of each stub groove 36 can also be any value for each individual stub groove 36.

[0056] As shown in FIG. 4(b), the other second waveguide section 31b constituting the waveguide section 30 also has a rectangular parallelepiped shape that divides the rectangular parallelepiped structure of the waveguide section 30 into approximately two halves in the longitudinal direction, and a groove section 35b that will become the waveguide 35 is formed on one side surface 32b facing the other first waveguide section 31a side, from one end section 33 to the other end section 34 in the longitudinal direction (Y direction).

[0057] The second waveguide section 31b has an arrangement structure of the grooves 35b and stub grooves 36 on one side surface 32b that is the same as the arrangement structure of the grooves 35a and stub grooves 36 on one side surface 32a of the first waveguide section 31a, except that the arrangement of each element when viewed from the front is reversed left to right compared to the arrangement structure of the grooves 35a and stub grooves 36 on one side surface 32a of the first waveguide section 31a shown in Figure 4(a).

[0058] The second waveguide section 31b also has tapered sections 35b1 (see FIG. 4(b)) toward both ends, which correspond to the tapered sections 35a1 toward both ends (one end 33, the other end 34) of the first waveguide section 31a. The tapered sections 35a1 and 35b1 are determined by the cross-sectional shapes of the cavity at both ends and the cross-sectional shapes of the opening surface, and are not limited to a structure in which the height (Z direction) gradually increases toward both ends, but may also have a structure in which the height gradually decreases toward both ends. For the same reason, the tapered sections 35a1 and 35b1 may have a structure in which not only the height but also the width (X direction) gradually changes (becomes wider or narrower) toward both ends.

[0059] The first waveguide portion 31a and the second waveguide portion 31b are made of, for example, aluminum, copper, or brass. In some cases, the entire surfaces of the side surfaces 32a and 32b on which the grooves 35a and 35b and the slab groove 36 are formed are gold-plated.

[0060] The first waveguide section 31a and the second waveguide section 31b shown in FIG. 4 are arranged so that one end portion 33 faces each other and the other end portion 34 faces each other, and one side surface 32a, 32b (or the intermediate surface between the two when there is a gap) of each is used as a plane of symmetry (magnetic wall), thereby having an external appearance structure as shown in FIG. 5(a) when viewed from the side.

[0061] In the waveguide section 30, groove 35a of first waveguide section 31a and groove 35b of second waveguide section 31b face each other to form waveguide 35 shown by the dotted line in FIG. 5(a). In the waveguide section 30, for example, one end 33 (see FIG. 4) of waveguide 35 functions as an input port 37, and the other end 34 (see FIG. 4) of waveguide 35 functions as an output port 38. The waveguide section 30 is designed to be connected to other waveguide components via input port 37 and output port 38, respectively. The waveguide section 30 has tapered sections 35a1 and 35b1 near both ends of waveguide 35, and the lengths of the tapered sections are set to an appropriate length taking into account connection with waveguide components.

[0062] When the first waveguide section 31a and the second waveguide section 31b are arranged opposite each other, the appearance structure of the waveguide section 30 (see FIG. 5(a)) viewed from the front is as shown in FIGS. 5(b), 5(c), and 5(d). FIG. 5(b) shows a structure in which the first waveguide section 31a and the second waveguide section 31b abut on each other at the symmetry planes (32a, 32b) described above, and there is no gap G between the first waveguide section 31a and the second waveguide section 31b (gap = G0). FIG. 5(c) shows a structure in which the gap G is a gap G1 that is larger than the gap G0, and FIG. 5(d) shows a structure in which the gap G is a gap G2 that is even larger than the gap G1. 5(b), (c), and (d), the end of the waveguide section 30 extending toward the front of the drawing (paper surface) forms the input port 37, and the end of the waveguide section 30 extending toward the back of the paper surface forms the output port 38. In Figures 5(b), (c), and (d), the input port 37 and the output port 38 are denoted by the reference numerals 37 (38) for convenience.

[0063] In the multiplexer 10 serving as a basic unit according to this embodiment, the waveguide section 30 has a characteristic in which its frequency characteristics (passband) change depending on the size of the gap G between the first waveguide section 31a and the second waveguide section 31b. For example, in FIG. 5, when there is no gap G between the first waveguide section 31a and the second waveguide section 31b (G=G0) (see FIG. 5(b)), when the gap G is G1 (see FIG. 5(c)), and when the gap G is G2 (see FIG. 5(d)), the waveguide section 30 has a frequency characteristic in which the passband changes downward as the gap G increases, i.e., as the gap G changes from G0 to G2. As an example, in FIGS. 5(b), 5(c), and 5(d), it is assumed that the frequency bands f1, f2, and f3 (f1>f2>f3) are set as the passbands corresponding to the gaps G0, G1, and G2, respectively.

[0064] The multiplexer 10 serving as a basic unit according to this embodiment is configured to be able to variably control the filter characteristics of the waveguide section 30 not only by variably controlling the gap G described above, but also by varying the configuration (position, depth, shape, etc.) of the stub groove 36 (see FIG. 4) formed in association with the waveguide 35. For example, in the waveguide section 30 of the multiplexer 10 serving as a basic unit according to this embodiment, the longer the stub length l2 of the stub groove 36 formed in the first waveguide section 31a and the second waveguide section 31b, the lower the band in which the cutoff frequency (center frequency in the BPF) can be set.

[0065] Regarding a method for realizing the waveguide section 30 used in the multiplexer 10 configured with the basic units according to this embodiment, for example, when the gap G between the first waveguide section 31 a and the second waveguide section 31 b is “0 (zero),” the highest frequency band may be designed by the stub length l2, stub height h2, etc. of the stub groove 36, and then the gap G may be increased to lower the frequency.

[0066] Returning to FIG. 3 again, the configuration of the gap adjustment section 40 of the multiplexer 10 as the basic unit according to this embodiment will be described.

[0067] In multiplexer 10 shown in FIG. 3, waveguide section 30 has an overall rectangular parallelepiped appearance with the Y direction as the longitudinal direction, the X direction as the width direction (short direction), and the Z direction as the height direction, as described above, and first waveguide section 31a and second waveguide section 31b are configured such that gap G between them can be variably controlled by gap adjustment section 40.

[0068] 3, the gap adjustment section 40 of the waveguide section 30 is composed of a first stage 41, a second stage 42, and a gap adjustment mechanism 43. The first stage 41 has a base section 41a, a stage main section 41b, and side walls 41c and 41d provided on both the left and right sides, forming a second stage housing section 41e surrounded by the base section 41a, the stage main section 41b, and the side walls 41c and 41d. Here, the stage main section 41b has an upper surface 41f that has a planar shape similar to the bottom surface of the first waveguide section 31a of the waveguide section 30. The first waveguide section 31a is fixed to the upper surface 41f of the stage main section 41b by its lower surface.

[0069] The second stage 42 has an upper surface 42a that has a planar shape equivalent to the lower surface of the second waveguide section 31b of the waveguide section 30. The length of the second stage 42 in the Y direction is slightly shorter than the distance between the side walls 41c, 41d that constitute the second stage housing section 41e of the first stage 41, and the second stage 42 is housed in the second stage housing section 41e such that movement in the Y direction is restricted and movement in the X direction is only permitted.

[0070] Here, the second stage 42 is accommodated in the second stage accommodation portion 41e of the first stage 41 while remaining parallel to the stage main portion 41b of the first stage 41 in the longitudinal direction (Y direction) and movable in both forward and backward directions (directions of arrow A) in the lateral direction (X direction). A screw hole 42c that penetrates the second stage 42 in the X direction is formed near the center of a side surface 42b opposite the first stage 41 and is threadedly engaged with a screw body 51 of the gap adjustment mechanism 43. The second waveguide portion 31b is fixed to the upper surface 42a of the second stage 42 by its lower surface.

[0071] The gap adjustment mechanism 43 is composed of a motor 50 that is fixedly attached, and a screw body 51 that extends in the X direction, screws into a screw hole 42c formed in the side surface 42b of the second stage 42, and is rotated by the motor 50.

[0072] The gap adjustment mechanism 43 rotates the screw body 51 in one direction or the opposite direction using the motor 50, thereby moving the second stage 42, which is screwed into the screw body 51 via the screw hole 42c, forward or backward in the X direction (in the direction of arrow A). As the second stage 42 moves, the second waveguide section 31b, which is fixed to the upper surface 42a of the second stage 42, moves in the direction of arrow A relative to the first waveguide section 31a while maintaining the parallelism of their symmetry planes (one side surface 32a, 32b). This makes it possible to appropriately variably control the size of the gap G between the first waveguide section 31a and the second waveguide section 31b while maintaining their parallelism.

[0073] In the multiplexer 10 as a basic unit according to this embodiment, the screw body 51 of the gap adjustment mechanism 43 is rotationally driven by the motor 50, and the gap G between the first waveguide portion 31a and the second waveguide portion 31b of the waveguide section 30 is variably controlled to, for example, G0, G1, or G2. This allows the multiplexer 10 to achieve the function of a waveguide-type BPF (see FIG. 2) in which, while being a single waveguide structure, each passband within a frequency range from f1 to f2' can be set as desired.

[0074] In Figure 3, an example of the gap adjustment unit 40 is shown in which the first stage 41 is fixed and the second stage 42 is moved, but this is not limited to this, and the gap adjustment unit 40A may be configured as a modified example having a structure in which both the first stage and the second stage are moved.

[0075] Fig. 5(e) shows a schematic configuration of a gap adjustment unit 40A according to a modified example. As shown in Fig. 5(e), the gap adjustment unit 40A according to the modified example includes a first stage 52a and a second stage 52b on which the first waveguide portion 31a and the second waveguide portion 31b of the waveguide filter 20 are placed so as to face each other, and motors 50a and 50b that rotate and drive the screw bodies 51a and 51b so as to move the first stage 52a and the second stage 52b back and forth in a direction perpendicular to the longitudinal direction of the waveguide portion 30 so as to change the gap G between the first waveguide portion 31a and the second waveguide portion 31b. Threaded holes 52a1 and 52b1 that threadably engage with the screw bodies 51a and 51b are formed on one side surfaces of the first stage 52a and the second stage 52b, respectively.

[0076] By providing the gap adjuster 40A having the above configuration in the waveguide filter 10, the waveguide filter 10 can easily and continuously vary the gap G between the first waveguide portion 41a and the second waveguide portion 41b by simultaneously moving the first stage 42a and the second stage 42b in directions toward or away from each other (moving them symmetrically about the plane of symmetry) using the motors 50a, 50b. Furthermore, by employing the gap adjuster 40A that can move the first stage 42a and the second stage 42b symmetrically about the plane of symmetry, the waveguide filter 20 can obtain better filter characteristics than when using a gap adjuster 40 (see FIG. 3) that fixes the first stage 41 and moves the second stage 42.

[0077] The motors 50a and 50b described above constitute the driving means of the present invention. The first stage 52a and the second stage 52b constitute the first stage member and the second stage member of the present invention, respectively.

[0078] As described above, the multiplexer 10 as a basic unit shown in FIG. 1 can realize a structure in which the passband can be varied by using the waveguide filter 20 equipped with the gap adjustment unit 40 or the gap adjustment unit 40A described in FIGS. 3 to 5 as the BPFs 20a1 and 20b1.

[0079] Furthermore, the multiplexer having a structure for varying the passband according to the present invention is not limited to the configuration of the basic unit shown in FIG. 1, and it is also possible to realize desired filter characteristics by variously combining the basic unit or a unit obtained by modifying the basic unit.

[0080] Configuration examples of multiplexers 10-1, 10-2, and 10-3 formed by combining basic units are shown in FIGS. 6 to 8. Each of the multiplexers 10-1, 10-2, and 10-3 includes the configuration of the basic unit described above, that is, a portion where filters such as a BPF and an HPF (an LPF can also be used) are arranged between two hybrids such as a BLC. The multiplexer 10-1 shown in FIG. 6 is composed of an HPF with a cut-off frequency fc1 (the passband is a frequency higher than fc1) and a BPF with a passband f2 (where f2 < fc1). In the multiplexer 10-1, when the frequency of the signal input from the Input port is within the passband of the HPF (higher than fc1), the signal passes through the HPF and appears at the Couple port of the subsequent-stage BLC. Therefore, a signal with a frequency fout > fc1 is extracted from the Output1 port. When the frequency of the signal input from the Input port is lower than fc1, the signal is reflected and input to the BPF through the Input port in front of the BPF from the Isolated port in front of the HPF. If the signal frequency is within the passband of the BPF (f2), it appears at the Couple port in the subsequent stage of the BPF, and a signal with fout = f2 is extracted from the Output2 port. Furthermore, when the signal is lower than f2, the signal outside the BPF band is reflected and appears at the Isolated port in the previous stage. Therefore, a signal with fout < f2 is extracted from the Output3 port. As described above, according to the configuration of the multiplexer 10-1, the input signal is divided and extracted into three frequency bands.

[0081] The multiplexer 10-2 shown in FIG. 7 extracts the frequency of the signal input from the Input port in the passbands (f1, f2, f3, f4) characterized by four BPFs and outputs it from each port. As shown in FIG. 7, it is composed of four BPFs with passbands f1, f2, f3, f4 and a HPF with a cut-off frequency fc1 (the passband is frequencies higher than fc1), and f1 < f2 < fc1 < f3 < f4. When the signal input from the Input port is higher than fc1, it passes through the HPF, and if the signal is within the band of f4, it passes through the BPF of f4 and is output from Output4. If it is outside the band of f4, it is reflected, and among them, the signal within the band of f3 passes through the BPF of f3 and is output from Output3. Similarly, when the input signal is lower than fc1, the signal within the band of f1 is extracted and output from Output1, and the signal within the band of f2 is extracted and output from Output2.

[0082] As another example of the combination of multiple basic units, a configuration may be adopted in which multiple basic units (two in this example) are switched by a switch or the like, such as the multiplexer 10-3 shown in FIG. 8. In the multiplexer 10-3, signals with frequencies corresponding to the passbands of the respective BPFs are extracted and output from the four Output ports. In this configuration, overlap between f1 and f2 and between f3 and f4 is not allowed, but overlap with another unit (for example, f1 and f3, f2 and f4, f1 and f4, etc.) is allowed.

[0083] Additional paragraph In the example shown in FIG. 8, a switch is used for switching the basic units, but it is not limited to this, and a configuration in which branching is performed by a power divider, a directional coupler, or the like may also be adopted.

[0084] In the present invention, multiplexer configurations other than those shown in Figures 6 to 8 are also possible. In any of these, for example, a basic unit includes a first hybrid (hybrid 18a1 in Figure 1), a second hybrid (hybrid 19a1 in Figure 1), a first filter (BPF 20a1 in Figure 1), and a second filter (BPF 20b1 in Figure 1), and multiple basic units are sequentially connected so that port P1 of the first hybrid of the subsequent basic unit is connected to port P4 of the first hybrid or port P3 of the second hybrid of the previous basic unit, and the first and second filters of the previous and subsequent basic units have variable passbands so that overlapping bands are formed through consecutive bands. Here, the first and second filters of each basic unit can be any one of BPF, HPF, and LPF, or a combination of multiple types.

[0085] Next, an embodiment of a multiplexer other than those shown in Figures 6 to 8, which is based on the multiplexer 10 (basic unit) shown in Figure 1, will be described with reference to Figures 9 and 10. This embodiment relates to a multiplexer 10A that combines multiple basic units (two basic units in this example) that can select adjacent frequency ranges, and can operate with a wider frequency range (see Figure 10(f)) than the frequency range in the case of a single basic unit (see Figure 2). This multiplexer 10A is intended for use in, for example, a spectrum analyzer 1 (see Figure 11), and as shown in Figure 9, has a configuration including multiplexers 10-11 and 10-12 that are made up of basic units (see Figure 1).

[0086] In a multiplexer 10A according to one embodiment of the present invention, one multiplexer 10-11 is configured with an input-side hybrid 18a1 having ports P1, P2, P3, and P4, an output-side hybrid 19a1 having the same structure, a BPF 20a1 consisting of two filters with approximately identical characteristics connected in parallel between the hybrids 18a1 and 19a1, and a BPF 20b1 connected to port P4 of the input-side hybrid 18a1, as described with reference to Fig. 1. Here, it is assumed that the frequency bands f1 and f3 (see Figs. 10(b) and 10(c)) are set as the initial (default) passbands of the BPFs 20a1 and 20b1, respectively.

[0087] The other multiplexer 10-12 is configured with an input-side hybrid 18a2 having ports P1, P2, P3, and P4, an output-side hybrid 19a2 having the same structure, a BPF 20a2 consisting of two filters with approximately identical characteristics connected in parallel between the hybrids 18a2 and 19a2, and a BPF 20b2 connected to port P4 of the input-side hybrid 18a2. Here, it is assumed that the frequency bands f5 and f7 (see FIGS. 10(d) and 10(e)) are set as default passbands for the BPFs 20a2 and 20b2, respectively.

[0088] In multiplexer 10A, hybrids 18a1 and 19a1 of multiplexer 10-11 and hybrids 18a2 and 19a2 of multiplexer 10-12 have the same functions. The only difference between BPFs 20a1 and 20b1 of multiplexer 10-11 and BPFs 20a2 and 20b2 of multiplexer 10-12 is the compatible filter characteristics (passband).

[0089] Regarding the passbands, the frequency bands f1 and f3 selected by the BPFs 20a1 and 20b1 of the multiplexer 10-11 in the default settings do not overlap with each other, as shown in Fig. 10(a), for example. Similarly, the frequency bands f5 and f7 selected by the BPFs 20a2 and 20b2 of the multiplexer 10-12 in the default settings do not overlap with each other.

[0090] Here, BPF 20a1 and BPF 20b1 of multiplexer 10-11 have passband varying means 40a-1 and 40b-1 and passband varying means 40c-1, respectively. The passband varying functions of these passband varying means 40a-1, 40b-1, and 40c-1 make it possible for multiplexer 10-11 to vary the passband from f1 to f1' (= f2) or from f3 to f3' (= f4) in accordance with the size of gap G in waveguide section 30, as shown in Figures 10(b) and 10(c).

[0091] Furthermore, the BPFs 20a2 and 20b2 of the multiplexer 10-12 have passband varying means 40a-2, 40b-2 and passband varying means 40c-2, respectively. The passband varying functions of these passband varying means 40a-2, 40b-2, and 40c-2 make it possible for the passband of the multiplexer 10-12 to be varied, for example, from f5 to f5' (= f6) or from f7 to f7' (= f8) according to the size of the gap G in the waveguide section 30, as shown in Figures 10(d) and 10(e).

[0092] Therefore, the entire multiplexer 10A including multiplexers 10-11 and 10-12 can variably control eight passbands f1 to f8 having overlapping bands ol1, ol2, ol3, ol4, ol5, ol6, and ol7, as shown in FIG. 10(f).

[0093] (Spectrum analyzer using multiplexer 10A) Next, an example of application of the multiplexer 10A according to this embodiment to a spectrum analyzer 1 will be described. Fig. 11 is a diagram showing a general configuration of a spectrum analyzer 1 that uses the multiplexer 10A. The spectrum analyzer 1 is assumed to have a function for analyzing millimeter-wave band signals.

[0094] The spectrum analyzer 1 according to this embodiment includes a frequency conversion section 100, a detector 120, a control section 150, an operation section 160, and a display section 161, and also includes a multiplexer 10A having the above-described configuration in front of the frequency conversion section 100. The multiplexer 10A is arranged so that an input port 37 can input a signal under test as an RF Input, and an output port 38 can send an output signal to the input side of the frequency conversion section 100 (see FIG. 9).

[0095] The frequency conversion section 100 is configured to include a mixer 111 , a local signal generator 112 , and a filter 113 .

[0096] Mixer 111 is a functional unit that functions as frequency conversion means for converting the signal under test from an RF frequency to an intermediate frequency signal (IF frequency) and outputting the signal by mixing the signal of each frequency component (RF frequency) in which spurious waves are suppressed and output from multiplexer 10A with a local signal input from local signal generator 112.

[0097] Local signal generator 112 generates a local signal to be sent to mixer 111 based on a local signal (reference signal) input from local oscillation signal source 9 .

[0098] The filter 113 is a filter function unit that inputs the IF signal that has been frequency converted by the mixer 111, passes only signals of frequency components in a predetermined band of the input IF signal, and inputs them to the detector 120.

[0099] The detector 120 is a processing circuit that detects the intensity of the signal (IF) of each band that passes through the filter 113 and is input.

[0100] The control unit 150 has a control function for comprehensively controlling the entire spectrum analyzer 1 including the multiplexer 10, and also has a gap variable control unit 151, a frequency sweep control unit 152, and a spectrum data acquisition unit 153. The control unit 150 may be a control unit of the spectrum analyzer 1 itself, or may be configured as a separate device such as a PC (personal computer).

[0101] The gap variable control unit 151 is a functional unit that variably adjusts the gap G between the first waveguide portion 31a and the second waveguide portion 31b of the multiplexer 10A within a range from G0 to G2 (see FIGS. 5(b), 5(c), and 5(d)) by rotating the motors 50a and 50b of the gap adjustment mechanism 43A (see FIG. 5(e)) of the multiplexer 10A in one direction or the other, for the passband variable means 40a-1, 40b-1, and 40c-1 and the passband variable means 40a-2, 40b-2, and 40c-2, respectively. The gap variable control unit 151, together with gap variable control units 151D and 151E described below, constitutes the passband variable control means of the present invention.

[0102] The frequency sweep control unit 152 is a functional unit that performs frequency sweep control to change the frequency of the local signal that the local signal generator 112 outputs to the mixer 111 within a specified frequency range, based on the local signal (reference signal) input from the local oscillation signal source 9.

[0103] The spectrum data acquisition unit 153 is a part that acquires spectrum data including the intensity of signal components in a desired frequency band within the frequency range to be analyzed detected by the detector 120, and performs display control on the display unit 161, etc.

[0104] The operation unit 160 has input means such as various keys, switches, buttons, etc., and is operated by the user when making various settings related to the measurement of the signal under measurement, etc. The display unit 161 is configured, for example, with a liquid crystal display, etc., and is a functional unit that displays a setting screen related to the measurement of the signal under measurement, measurement results, etc.

[0105] 11, a millimeter-wave band signal under test (input signal) is applied to mixer 111 of frequency conversion section 100 via multiplexer 10A and mixed with a local signal output from local signal generator 112, and a signal in a predetermined intermediate (IF) frequency band is extracted from the mixed output by filter 113. The frequency of the local signal is swept variably by frequency sweep control section 152 of control section 150 in accordance with a desired frequency range to be analyzed, and signal components in the desired frequency range to be analyzed are extracted as intermediate frequency band signals over time, and the intensity of these signals is detected by detector 120.

[0106] For ease of explanation, an example is shown in which the frequency conversion process (heterodyne conversion) of the frequency conversion unit 100 is performed only once. However, in order to accurately analyze high-frequency signals such as those in the millimeter wave band, the frequency conversion process is performed multiple times to convert the signals into an intermediate frequency band that can be digitally processed.

[0107] In the control unit 150, the spectrum data acquisition unit 153 stores the signal strength detected by the detector 120 for each analysis target frequency as spectrum data, for example, in accordance with the analysis target frequency set by the operation unit 160, and displays the spectrum data on the display unit 161.

[0108] The gap variable control unit 151 drives and rotates the motors 50a and 50b of the gap adjustment mechanism 43A (see FIG. 5(e)) for the passband variable means 40a-1, 40b-1, and 40c-1 and the passband variable means 40a-2, 40b-2, and 40c-2 of the multiplexer 10A, respectively, in accordance with a preset frequency to be analyzed, and variably controls the gap G between the first waveguide portion 31a and the second waveguide portion 31b of the multiplexer 10A to a value corresponding to a desired passband within the frequency range to be analyzed.

[0109] The frequency sweep control unit 152 performs sweep control of the frequency corresponding to the pass band set for the multiplexer 10A by the variable control of the gap G by the gap variable control unit 151.

[0110] 11, the signal under measurement as an input signal (RF Input) to input port 37 of multiplexer 10A is, for example, a signal (fRF) in the frequency range of 255 to 315 GHz, and the output signal (IF Output) from output port 38 is, for example, a signal (fIF) in the frequency range of 23 to 31 GHz. That is, the spectrum analyzer 1 according to this embodiment takes in, for example, a received signal received from a mobile phone (5G, LTE, XG-PHS, W-CDMA, CDMA2000, GSM, etc.) or various wireless communications (WLAN, Bluetooth, GPS, ISDBT, etc.) as an input signal (RF Input), and can measure the spectral characteristics of a desired frequency component after suppressing spurious waves using multiplexer 10A in the front-end circuit.

[0111] Next, the signal measurement control operation of the spectrum analyzer 1 according to this embodiment will be described with reference to the flowchart shown in FIG.

[0112] In this example, the spectrum analyzer 1 uses a multiplexer 10A, inputs the signal under test to the multiplexer 10A from the input port 37, and sequentially extracts a signal in a predetermined desired frequency band from the signal under test, for example, one of frequency bands f1, f2, f3, f4, f5, f6, f7, or f8, outputs the extracted signal to the output port 38, and measures its spectral characteristics.

[0113] To perform the above measurement, the user operates the operation unit 160 to set the sweep frequency range (frequency range to be analyzed) of the spectrum analyzer 1 (step S1). Parameters to be set here include, for example, the center frequency and sweep frequency span of each of the frequency bands f1, f2, f3, f4, f5, f6, f7, and f8, the start frequency and stop frequency, and the start frequency and sweep frequency span.

[0114] Next, the control unit 150 calculates the passband (one of frequency bands f1, f2, f3, f4, f5, f6, f7, and f8 (see FIG. 10)) to be selected by the multiplexer 10 and the setting conditions (LO setting) of the local frequency (LO) based on the sweep frequency range set in step S1 (step S2).

[0115] Subsequently, the gap variable control unit 151 adjusts and controls the gap G between the first waveguide portion 31a and the second waveguide portion 31b of each of the multiplexers 10-11 and 10-12 constituting the multiplexer 10A so that it becomes one of the gap Gs corresponding to the passband calculated in step S2, for example, G0, G1, or G2 (see FIGS. 5(b), (c), and (d)) (step S3). At this time, the gap variable control unit 151 sends control signals (gap adjustment control signals) corresponding to the calculated passband to the motors 50a and 50b of the gap adjustment mechanism 43A, targeting the passband variable means 40a-1, 40b-1, and 40c-1 and the passband variable means 40a-2, 40b-2, and 40c-2, respectively, and drives the motors 50a and 50b to rotate until the gap G becomes a value corresponding to the calculated passband. In step S3, control is also performed to set a local frequency based on the LO setting calculated in step S2 for frequency conversion in the frequency conversion unit 100.

[0116] After completing the adjustment control of the gap G and the setting of the local frequency in step S3, the control unit 150 inputs the frequency component corresponding to the adjusted gap G that passes through the waveguide 35 of the multiplexer 10A from the output port 38 to the frequency conversion unit 100, converts the frequency, and inputs it to the detector 120 (step S4).

[0117] Furthermore, the control unit 150 controls the detector 120 to measure the spectral characteristics of the signal of the frequency component (desired frequency band passed through the multiplexer 10A) after frequency conversion by the frequency conversion unit 100 (step S5). Here, the spectrum data acquisition unit 153 acquires spectrum data including the intensity of any one of the signal components of the desired frequency bands f1, f2, f3, f4, f5, f6, f7, and f8 detected by the detector 120, and performs spectrum display control to display the spectrum data on the display unit 161.

[0118] 12, if there is only one passband (frequency band) to be selected in step S2, the signal measurement operation is terminated after performing the processes of adjusting the gap G in step S3, frequency conversion in step S4, and measuring the spectrum characteristics in step S5. If there are multiple passbands to be set in step S2, the processes of steps S3, S4, and S5 are repeatedly performed for each passband, and then the signal measurement operation is terminated.

[0119] As a modified example of the spectrum analyzer 1 according to this embodiment, a multiplexer 10 (see FIG. 1) having a basic unit configuration may be used instead of the multiplexer 10A shown in FIG. 9. Also, a gap adjustment mechanism 43 (see FIG. 3) may be used instead of the gap adjustment mechanism 43A.

[0120] In the spectrum analyzer 1 according to the modified example using the multiplexer 10, the signal under measurement is input to the multiplexer 10, and a signal in a predetermined desired frequency band, for example, any one of frequency bands f1, f2, f3, and f4, is extracted from the signal under measurement by the multiplexer 10, and its spectral characteristics can be measured. In the spectrum analyzer 1 according to the modified example, the basic measurement operation can be realized according to the flowchart shown in FIG.

[0121] (Signal analyzer 2 using multiplexer 10A) The multiplexer 10A (see FIG. 9) according to the above embodiment is not limited to the spectrum analyzer 1 shown in FIG.

[0122] 13 is a diagram showing a general configuration of a signal analyzer 2 that uses a multiplexer 10A. The signal analyzer 2 has a frequency conversion unit 100D, an analog-to-digital converter (ADC) 125, a control unit 150D, an operation unit 160, and a display unit 161, and is equipped with a multiplexer 10A having the above-mentioned configuration in front of the frequency conversion unit 100D. The multiplexer 10A is arranged so that an input port 37 can input a signal under test, which is an RF input, and an output port 38 can send an output signal to the input side of the frequency conversion unit 100D (see FIG. 9).

[0123] The frequency conversion section 100D is configured to include a mixer 111D, a local signal generator 112D, and a filter 113D.

[0124] Mixer 111D mixes the signal (RF frequency) of each frequency component in which spurious waves are suppressed and output from multiplexer 10A with the local signal input from local signal generator 112D, thereby converting the signal under test from RF frequency to an intermediate frequency signal (IF frequency) and outputting it.

[0125] Based on a local signal (reference signal) input from local oscillation signal source 9, local signal generator 112D generates a local signal to be sent to mixer 111D.

[0126] The filter 113D is a filter function unit that receives the IF signal frequency-converted by the mixer 111D, passes only signals of frequency components in a predetermined band of the received IF signal, and inputs them to the ADC 125.

[0127] The ADC 125 is a functional unit that converts the signal (signal under test) that has passed through the multiplexer 10A and has been frequency-converted by the frequency conversion unit 100D from an analog signal to a digital signal.

[0128] The control unit 150D has a variable gap control unit 151D, a frequency control unit 152D, and a signal analysis unit 153D. The variable gap control unit 151D is the same as that provided in the control unit 150 of the spectrum analyzer 1 (see FIG. 7).

[0129] The frequency control unit 152D controls the setting of a local frequency so that a signal within a specified analysis target frequency range can be received when the frequency conversion unit 100D converts the frequency of the signal under test. The local signal generator 112D constituting the frequency conversion unit 100D is configured to be able to vary the local frequency in accordance with the received RF frequency. Therefore, the frequency control unit 152D may be configured to drive and control the local signal generator 112D and sweep the local frequency.

[0130] The signal analysis unit 153D executes a process of analyzing the waveform of the signal (signal under measurement) converted from a digital signal by the ADC 125, specifically, a process of generating waveform analysis data for displaying the digital signal as a waveform such as a spectrum.

[0131] The signal analysis process of the signal analyzer 2 having the above configuration follows the same flow up to step S3 as the signal measurement operation of the spectrum analyzer 1 shown in FIG. 11 (see FIG. 12). In the subsequent signal analysis operation, after the signal analyzer 2 completes the gap G adjustment control and local frequency setting in step S3, the control unit 150E inputs the frequency component corresponding to the adjusted gap G passing through the waveguide 35 of the multiplexer 10A from the output port 38 to the frequency conversion unit 100 for frequency conversion, and inputs the converted signal to the ADC 125. The ADC 125 converts the frequency-converted signal from an analog signal to a digital signal and inputs the converted signal to the signal analysis unit 153D. The signal analysis unit 153D generates waveform analysis data from the digital signal input from the ADC 125, which is used to display the waveform of the digital signal, such as a spectrum. The control unit 150D controls signal analysis, such as displaying the waveform analysis data generated by the signal analysis unit 153D on the display unit 161.

[0132] It goes without saying that the signal analyzer 2 according to this embodiment may also be configured to use a multiplexer 10 (see FIG. 1) having a basic unit configuration instead of the multiplexer 10A shown in FIG. 9. Also, the gap adjustment mechanism 43 (see FIG. 3) may be used instead of the gap adjustment mechanism 43A.

[0133] (Signal Generator 3 Using Multiplexer 10E) The multiplexer 10A (see FIG. 9) according to the above modification can be applied to the spectrum analyzer 1 shown in FIG. 11, the signal analyzer 2 shown in FIG. 13, and also to, for example, a signal generating device 3 that performs a receiving sensitivity test on a DUT.

[0134] 14 is a diagram showing a general configuration of a signal generating device 3 that uses the above-described multiplexer 10A as the multiplexer 10E. The signal generating device 3 is assumed to be a test signal generating device that generates test signals for testing the receiving sensitivity of millimeter-wave band signals for a DUT.

[0135] The signal generating device 3 according to this embodiment includes a frequency conversion unit 100E, a signal generating unit 130, a control unit 150E, an operation unit 160, a display unit 161, and a multiplexer 10E provided in a stage subsequent to the frequency conversion unit 100E. The frequency conversion unit 100E is configured with a mixer 111E, a local signal generator 112E, and a filter 113E, and the control unit 150E is configured with a gap variable control unit 151E, a frequency control unit 152E, and a signal generation control unit 153E.

[0136] In the signal generating device 3, under the control of the signal generation control unit 153E, the frequency conversion unit 100E provides the test signal in the intermediate frequency band output from the signal generating unit 130 together with the local signal output from the local signal generator 112E to the mixer 111E to perform processing to convert them into a millimeter wave band signal. At this time, the frequency conversion unit 100E changes the frequency of the local signal using the frequency control unit 152E in accordance with a test target frequency set by, for example, the operation unit 160 to test the DUT, and sends the frequency-converted signal to a subsequent stage.

[0137] The multiplexer 10E provided in the subsequent stage of the frequency conversion unit 100E can be the above-mentioned multiplexer 10 (see FIG. 1), multiplexer 10A (see FIG. 9), etc., but here we will particularly explain a configuration using multiplexer 10A (see FIG. 9).

[0138] That is, in the signal generating device 3, the multiplexer 10E is arranged so that the input port 37 is connected to the output side of the frequency converting section 100E and the output port 38 is connected to the input side of the test signal (the side that transmits the test signal to the outside as RF Output), as shown in Fig. 14. The configuration of the multiplexer 10E in the signal generating device 3 is shown in Fig. 15. As shown in Fig. 15, the multiplexer 10E has a signal input / output path that is reversed from that of the multiplexer 10A (see Fig. 9) implemented in the above-mentioned spectrum analyzer 1 or signal analyzer 2 (a signal from the frequency converting section 100E is input to the input port 37 and output from the output port 38 to the RF output side). In this way, in the multiplexer 10E, a signal (a test signal input from the signal generating unit 130) converted to an RF frequency (for example, frequency bands f1, f2, f3, f4, f5, f6, f7, and f8) from the frequency conversion unit 100E side is input to the input port 37, and the input signal is sent out as a test signal, which is a PF Output, via the multiplexer 10E.

[0139] The test signal transmission control operation of the signal generator 3 when testing a DUT will be described with reference to the flowchart shown in FIG.

[0140] To test the DUT, the user performs an operation to set a frequency, i.e., a test target frequency, on the operation unit 160 (step S11). Parameters to be set here include, for example, the center frequency of each of the frequency bands f1, f2, f3, f4, f5, f6, f7, and f8, as well as the start frequency and stop frequency.

[0141] Next, the control unit 150E calculates the passband (one of frequency bands f1, f2, f3, f4, f5, f6, f7, and f8) to be selected by the multiplexer 10 and the LO setting based on the test frequency range set in step S11 (step S12).

[0142] Subsequently, the gap variable control unit 151 adjusts and controls the gap G between the first waveguide portion 31a and the second waveguide portion 31b of the multiplexer 10E to one of the gap Gs corresponding to the passband calculated in step S12, for example, G0, G1, or G2 (see FIGS. 3(b), (c), and (d)) (step S13). At this time, the gap variable control unit 151 sends control signals (gap adjustment control signals) corresponding to the calculated passband to the motors 50a and 50b of the gap adjustment mechanism 43A for the passband variable means 40a-1, 40b-1, and 40c-1 and the passband variable means 40a-2, 40b-2, and 40c-2, respectively, and drives the motors 50a and 50b to rotate until the gap G reaches a value corresponding to the calculated passband. In step S13, control is also performed to set a local frequency based on the LO setting calculated in step S12 for frequency conversion in the frequency conversion unit 100E.

[0143] After completing the adjustment control of the gap G and the setting of the local frequency in step S13, the control unit 150E outputs the frequency component corresponding to the adjusted gap G that passes through the waveguide 35 of the multiplexer 10E from the output port 38 to an RF transmission unit (not shown) (step S14).

[0144] Furthermore, the control unit 150E drives and controls the RF transmission unit to transmit the signal of the frequency component input from the output port 38 of the multiplexer 10E as a test signal (step S15).

[0145] It goes without saying that the signal generating device 3 according to this embodiment may also be configured to use a multiplexer 10 (see FIG. 1) having a basic unit configuration instead of the multiplexer 10A shown in FIG. 9. Furthermore, the gap adjustment mechanism 43 (see FIG. 3) may be used instead of the gap adjustment mechanism 43A as the passband varying means 40a-1, 40b-1, 40c-1 and the passband varying means 40a-2, 40b-2, 40c-2.

[0146] As described above, the multiplexer 10 according to this embodiment includes hybrids 18a1 and 19a1 each having a port P1 (Input), a port P2 (Through), a port P3 (Coupled), and a port P4 (Isolated) and configured as a circuit network for distributing or combining signals, a BPF 20a1 consisting of two filters with approximately the same characteristics connected in parallel between the hybrids 18a1 and 19a1, and a BPF 20b1 connected to the port P4 of the hybrid 18a1 and having a passband adjacent to the passband of the BPF 20a1. An input signal from port P1 is distributed to two BPFs 20a1, and if it is within the respective passbands, it passes through BPF 20a1, is combined by hybrid 19a1, and is output from port P3 of hybrid 19a1. On the other hand, if the input signal is outside the passband of the filter of BPF 20a1, it is reflected, combined by hybrid 18a1, and is output from port P4 to BPF 20b1. The configuration has passband varying means 40a, 40b, 40c that vary the passbands of BPFs 20a1, 20b1 within a band range in which overlapping bands are formed within a predetermined frequency range.

[0147] With this configuration, the multiplexer 10 of this embodiment can easily and continuously vary the passbands of the BPFs 20a1 and 20b1 using the passband varying means 40a, 40b, and 40c, without switching filters, and can therefore accommodate high-precision measurement, analysis, and testing of high-frequency signals with a simple and inexpensive structure.

[0148] Furthermore, the multiplexer 10 of this embodiment has a basic unit including hybrids 18a1, 19a1, BPF 20a1, and BPF 20b1, and is configured by sequentially connecting a plurality of basic units such that port P1 of hybrid 18a1 of a subsequent basic unit is connected to port P4 of hybrid 18a1 of a previous basic unit or port P3 of hybrid 19a1, and the BPFs 20a1 and 20b1 of the previous and subsequent basic units are configured to vary their passbands so that overlapping bands are formed through successive bands.

[0149] With this configuration, the multiplexer 10 according to this embodiment can construct a filter structure that can accommodate a desired extended passband using a simple structure by combining multiple basic units, and can also facilitate high-precision measurement, analysis, and testing of high-frequency signals.

[0150] Furthermore, in the multiplexer 10 according to this embodiment, the filters corresponding to the BPFs 20a1 and 20b1 of the respective basic units have a configuration in which any one of BPF, HPF, and LPF is used, or a combination of a plurality of types is used.

[0151] With this configuration, the multiplexer 10 according to this embodiment can easily realize a filter structure with desired specifications by combining a hybrid with one or more types of BPF, HPF, and LPF.

[0152] In the multiplexer 10 according to this embodiment, the BPFs 20a1 and 20b1 are configured by the waveguide filters 20, and the waveguide filters 20 each have a rectangular parallelepiped shape and include a first waveguide section 31a and a second waveguide section 31b, each of which has grooves 35a and 35b formed on one side surface 32a and 32b in the longitudinal direction, from one end 33 to the other end 34 in the longitudinal direction, to become a waveguide 35. The first waveguide section 31a and the second waveguide section 31b are formed on one side surface 32a and 32b. The waveguide 35 is formed by grooves 35a, 35b arranged facing each other, and the waveguide section 30 has a passband of the waveguide 35 that changes depending on a gap G between one side surface 32a of the first waveguide section 31a and one side surface 32b of the second waveguide section 31b, and gap adjustment mechanisms 43, 43A that constitute passband varying means 40a, 40b, 40c and vary the gap G in the waveguide section 30 so as to set a desired passband.

[0153] With this configuration, the multiplexer 10 according to this embodiment can easily realize the passband variable means 40a, 40b, 40c using the gap adjustment mechanisms 43, 43A that adjust the gap G between the first waveguide portion 31a and the second waveguide portion 31b of the waveguide filter 20.

[0154] Furthermore, in the multiplexer 10 according to this embodiment, the gap adjustment mechanism 43A includes a first stage 52a on which the first waveguide portion 31a is placed, a second stage 52b on which the second waveguide portion 31b is placed so as to face the first waveguide portion 31a, and motors 50a and 50b that drive the first stage 52a and the second stage 52b symmetrically with respect to the plane of symmetry so as to change the gap G between the first waveguide portion 31a and the second waveguide portion 31b.

[0155] With this configuration, the multiplexer 10 according to this embodiment can easily and continuously vary the gap G between the first waveguide portion 31 a and the second waveguide portion 31 b by driving the first stage 52 a and the second stage 52 b by the motors 50 a and 50 b so that they move symmetrically with respect to the symmetry plane, and can improve the filter characteristics when the passband is varied.

[0156] Furthermore, in the multiplexer 10 according to this embodiment, the waveguide section 30 is configured to input a signal to be measured in a predetermined frequency range to the waveguide 35, and to output frequency components in one of a plurality of overlapping frequency bands that matches the pass band corresponding to the gap G.

[0157] With this configuration, the multiplexer 10 of this embodiment can set a desired passband from among multiple passbands within a predetermined frequency range according to the gap G by varying the gap G using the gap adjustment mechanisms 43, 43A.

[0158] Furthermore, spectrum analyzer 1 according to this embodiment includes frequency conversion section 100 having filter 113 that supplies a signal under measurement in a predetermined frequency range to mixer 111 together with a local signal output from local signal generator 112, and extracts a signal in a predetermined intermediate frequency band from the mixed output, and detector 120 that detects the signal in the intermediate frequency band, and determines the spectral characteristics of the signal under measurement by changing the frequency of the local signal in accordance with the frequency to be analyzed. Furthermore, spectrum analyzer 1 has multiplexer 10A having the above-described configuration provided upstream of frequency conversion section 100, and also has gap variable control section 151 that drives and controls passband varying means 40a, 40b, 40c so that a passband corresponding to one frequency band of the frequencies to be analyzed is set, and the frequency components corresponding to one frequency band of the frequencies to be analyzed are measured via multiplexer 10A.

[0159] With this configuration, the spectrum analyzer 1 according to this embodiment can easily and continuously vary the passband without switching filters by varying the passbands of the BPFs 18a1 and 19a1 of the multiplexer 10A using the passband varying means 40a, 40b, and 40c, thereby enabling high-frequency signals to be measured with high precision using a simple and inexpensive structure.

[0160] Furthermore, the spectrum analyzer 1 according to this embodiment has a basic unit including hybrids 18a1, 19a1, BPF 20a1, and BPF 20b1, and multiplexer 10A is configured by combining a plurality of basic units 10-11 and 10-12, and BPFs 18a1 and 19a1 of each basic unit are configured to vary the passbands so that overlapping bands are formed through successive bands.

[0161] With this configuration, the spectrum analyzer 1 according to this embodiment can construct a multiplexer filter structure that can accommodate a desired extended passband by combining multiple basic units with a simple structure, and can easily accommodate high-precision measurement, analysis, and testing of high-frequency signals.

[0162] Furthermore, signal analyzer 3 according to this embodiment includes frequency conversion unit 100D having filter 113D that supplies a signal under measurement in a predetermined frequency range to mixer 111D together with a local signal output from local signal generator 112 and extracts a signal in a predetermined intermediate frequency band from the mixed output, and signal analysis unit 153D that converts the intermediate frequency band signal into a digital signal using ADC 125 and then analyzes the waveform of the digital signal. In signal analyzer 2 that analyzes the waveform of the signal under measurement by changing the frequency of the local signal in accordance with the frequency to be analyzed, multiplexer 10A having the above-described configuration is provided upstream of frequency conversion unit 100D, and gap variable control unit 151D that drives and controls passband variable means 40a, 40b, 40c so that a passband corresponding to one frequency band of the frequencies to be analyzed is included, and a signal of a frequency component corresponding to one frequency band of the frequencies to be analyzed is analyzed via multiplexer 10A.

[0163] With this configuration, the signal analyzer 2 according to this embodiment can easily and continuously vary the passbands without switching filters by varying the passbands of BPFs 18a1 and 19a1 using passband varying means 40a, 40b, and 40c, thereby enabling high-frequency signal analysis with high accuracy using a simple and inexpensive structure.

[0164] Furthermore, the signal generating device 3 according to this embodiment includes a frequency conversion section 100E that supplies a test signal in the intermediate frequency band output from the signal generating section 130 to a mixer 111E together with a local signal output from a local signal generator 112E to convert them into a signal in a predetermined frequency range, changes the frequency of the local signal in accordance with a test frequency for testing the DUT, and sends out the signal after frequency conversion by the frequency conversion section 100E as a test signal for the device under test. In the signal generating device 3, a multiplexer 10E having the above-described configuration to which the frequency-converted signal is input is provided downstream of the frequency conversion section 100E, and a gap variable control section 151E that drives and controls the passband variable means 40a, 40b, 40c so that a passband corresponding to one frequency band of the test frequencies is set, and the signal generating device 3 is configured to send out a test signal of a frequency component corresponding to one frequency band of the test frequencies that passes through the multiplexer 10E.

[0165] With this configuration, the signal generating device 3 according to this embodiment can easily and continuously vary the passbands without switching filters by varying the passbands of the BPFs 18a1 and 19a1 using the passband varying means 40a, 40b, and 40c, and can therefore support high-precision DUT testing of high-frequency signals with a simple and inexpensive structure.

[0166] Furthermore, the multiplexer control method according to this embodiment is a multiplexer control method in the spectrum analyzer 1, signal analyzer 2, or signal generator 3 that uses the multiplexer 10 having the above-described configuration, and includes a setting step (S1, S11) of setting an analysis target frequency or a test target frequency, a passband variable control step (S3, S13) of driving and controlling the passband variable means 40a, 40b, 40c so that a passband to be selected for the BPFs 18a1, 19a1 is set based on the set analysis target frequency or test target frequency, and a step (S4, S14) of extracting a frequency component corresponding to the analysis target frequency or the test target frequency that passes through the BPFs 18a1, 19a1 having the passband set by the passband variable means 40a, 40b, 40c.

[0167] With this configuration, the multiplexer control method according to this embodiment can be applied to the spectrum analyzer 1, the signal analyzer 2, or the signal generator 3, and by varying the passbands of the BPFs 18a1 and 19a1 using the passband varying means 40a, 40b, and 40c, the passbands can be easily and continuously varied without switching filters, thereby enabling high-precision measurement, analysis, and testing of high-frequency signals with a simple and inexpensive structure.

[0168] The multiplexers 10, 10A, the spectrum analyzer 1, the signal analyzer 2, the signal generating device 3, and the multiplexer control method according to the present invention are not limited to the configurations described in the above-described embodiments, and various modifications and applications are possible. [Industrial Applicability]

[0169] As described above, the present invention has the advantage of being able to easily change the passband without switching filters, and being able to measure, analyze, and test high-frequency signals with high precision using a simple and inexpensive structure, and is useful for multiplexers, spectrum analyzers, signal analyzers, signal generators, and multiplexer control methods in general that use multiplexers. [Explanation of symbols]

[0170] 1. Spectrum analyzer 2. Signal Analyzer 3. Signal Generator 9 Local Oscillator Signal Source 10, 10-11, 10-12, 10A, 10E multiplexers 18a1 Hybrid (First Hybrid) 19a1 Hybrid (Second Hybrid) 20a1 BPF (first filter) 20b1 BPF (second filter) 20 Waveguide Filter 30 Waveguide section 31a First waveguide section (first waveguide section) 31b Second waveguide section (second waveguide section) 32a, 32b one side 33 One end (one end) 34 Other end (other end) 35 Waveguide 40, 40A gap adjustment part 40a, 40b, 40c passband variable means 41 Stage 1 42 Stage 2 43, 43A Gap adjustment mechanism 50, 50a, 50b Motor (driving means) 52a First stage (first stage member) 52b Second stage (second stage member) 100, 100D, 100E frequency conversion unit 111, 111D, 111E Mixers 112, 112D, 112E Local Signal Generator 113, 113D, 113E filters 120 Detector 125 Analog-to-Digital Converter (ADC) 130 Signal Generator 150, 150D, 150E control unit 151, 151D, 151E Gap variable control section (passband variable control means) 152 Frequency sweep control section 152D, 152E frequency control section 153 Spectrum data acquisition unit 153D Signal analysis section 153E Signal generation control section 160 Operation section 161 Display section

Claims

1. a first hybrid (18a1) and a second hybrid (19a1) each having a port P1 (Input), a port P2 (Through), a port P3 (Couple), and a port P4 (Isolated) and configured as a circuit network for distributing or combining signals; a first filter (20a1) configured by two filters having approximately the same characteristics connected between the first hybrid and the second hybrid, one of the filters having a first passband variable means (40a) having an input side connected to the port P2 of the first hybrid and an output side connected to the port 1 of the second hybrid, and the other filter having a second passband variable means (40b) having an input side connected to the port P3 of the first hybrid and an output side connected to the port 4 of the second hybrid; a second filter (20b1) connected to the port P4 of the first hybrid and having a passband adjacent to the passband of the first filter; An input signal from the port P1 of the first hybrid is distributed to two of the first filters, and if the input signal is within the passband of each filter, the signal passes through the first filter, is combined in the second hybrid, and is output from the port P3 of the second hybrid. a multiplexer that, if the input signal is outside the passband of the first filter, reflects the signal, combines it in the first hybrid, and outputs it from the port P4 to the second filter; A multiplexer comprising passband varying means (40a, 40b, 40c) for varying the passbands of the first filter and the second filter so that overlapping bands are formed through successive bands.

2. A configuration including the first hybrid, the second hybrid, the first filter, and the second filter is defined as a basic unit, and a plurality of the basic units are sequentially connected so that the port P1 of the first hybrid of a subsequent basic unit is connected to the port P4 of the first hybrid of a previous basic unit or the port P3 of the second hybrid of a subsequent basic unit, 2. The multiplexer according to claim 1, wherein the first filter and the second filter of the preceding and succeeding basic units vary the passbands so that overlapping bands are formed through successive bands.

3. 3. The multiplexer according to claim 2, wherein the first filter and the second filter of each of the basic units have a configuration of one type of filter selected from the group consisting of a band-pass filter, a high-pass filter, and a low-pass filter, or a combination of multiple types of filters.

4. the first filter and the second filter are composed of a waveguide filter (20); The waveguide filter comprises: a waveguide section (30) comprising a first waveguide section (31a) and a second waveguide section (31b) each having a rectangular parallelepiped shape, each having a groove (35a, 35b) to be a waveguide (35) formed on one side surface (32a, 32b) in the longitudinal direction from one end (33) to the other end (34) in the longitudinal direction, the waveguide being formed by the groove when the first waveguide section and the second waveguide section are disposed opposite each other with the one side surface facing each other, and the pass band of the waveguide changing depending on the gap between the one side surface of the first waveguide section and the one side surface of the second waveguide section; 2. The multiplexer according to claim 1, further comprising a gap adjustment mechanism (43, 43A) constituting the passband variable means and varying the gap in the waveguide portion so as to set a desired passband.

5. The gap adjustment mechanism (43A) is a first stage member (52a) on which the first waveguide section is placed; a second stage member (52b) on which the second waveguide portion is placed so as to face the first waveguide portion; a driving means (50a, 50b) for driving the first stage member and the second stage member so as to be movable symmetrically with respect to a plane of symmetry so as to change the gap between the first waveguide portion and the second waveguide portion; 5. The multiplexer of claim 4, wherein:

6. 6. The multiplexer according to claim 5, wherein the waveguide section has a frequency characteristic in which a passband changes downward as a gap between the first waveguide section (31 a) and the second waveguide section (31 b) increases, and wherein a signal to be measured in the predetermined frequency range is input to the waveguide, and frequency components of one of the overlapping frequency bands that matches the passband corresponding to the size of the gap are output.

7. A spectrum analyzer (1) comprising: a frequency conversion section (100) having a filter (113) that supplies a signal under test in a predetermined frequency range to a mixer (111) together with a local signal output from a local signal generator (112), and extracts a signal in a predetermined intermediate frequency band from a mixed output obtained by mixing the signal under test and the local signal by the mixer; and a detector (120) that detects the signal in the intermediate frequency band, and that determines the spectral characteristics of the signal under test by changing the frequency of the local signal according to a frequency to be analyzed, The multiplexer (10A) according to claim 1 is provided in the preceding stage of the frequency conversion unit, a passband variable control means (151) for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the analysis target frequencies is set; A spectrum analyzer characterized in that frequency components corresponding to one frequency band of the analysis target frequencies are measured through the multiplexer.

8. a basic unit including the first hybrid, the second hybrid, the first filter, and the second filter; The multiplexer (10A) is configured by combining a plurality of the basic units (10-11, 10-12), 8. The spectrum analyzer according to claim 7, wherein the first filter and the second filter of each of the basic units vary the passbands so that overlapping bands are formed through successive bands.

9. A signal analyzer (2) comprising: a frequency conversion unit (100D) having a filter (113D) that supplies a signal under test in a predetermined frequency range to a mixer (111D) together with a local signal output from a local signal generator (112D), and extracts a signal in a predetermined intermediate frequency band from a mixed output obtained by mixing the signal under test and the local signal by the mixer; and a signal analysis unit (153D) that converts the signal in the intermediate frequency band into a digital signal by an ADC (125) and then analyzes the waveform of the digital signal, and that changes the frequency of the local signal according to a frequency to be analyzed, The multiplexer (10A) according to claim 1 is provided in the preceding stage of the frequency conversion unit, a passband variable control means (151D) for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the analysis target frequencies is set; A signal analyzer characterized in that a signal of frequency components corresponding to one frequency band of the target frequencies for analysis is analyzed through the multiplexer.

10. A signal generating device (3) having a frequency converting section (100E) that provides a test signal in an intermediate frequency band output from a signal generating section (130) to a mixer (111E) together with a local signal output from a local signal generator (112E) to convert the signal into a signal in a predetermined frequency range, changes the frequency of the local signal according to a test frequency for testing a device under test (DUT), and sends out the signal after frequency conversion by the frequency converting section as the test signal for the device under test, The multiplexer (10E) according to claim 1 is provided in a stage subsequent to the frequency conversion unit, to which the frequency-converted signal is input; a passband variable control means (151E) for driving and controlling the passband variable means so that the passband corresponding to one frequency band of the test target frequencies is set; a signal generator configured to transmit the test signal having a frequency component corresponding to one frequency band of the test target frequencies that passes through the multiplexer;

11. A method for controlling a multiplexer in a spectrum analyzer, a signal analyzer, or a signal generator using the multiplexer (10) according to claim 1, comprising: a setting step (S1, S11) of setting an analysis target frequency or a test target frequency; a passband variable control step (S3, S13) of driving and controlling the passband variable means so that the passbands to be selected for the first filter and the second filter are set based on the set analysis target frequency or test target frequency; a step (S4, S14) of extracting a frequency component corresponding to the analysis target frequency or the test target frequency that passes through the first filter and the second filter having the pass band set by the pass band variable means; A method for controlling a multiplexer, comprising:

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