JP2018152805A - Microwave equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve isolation performance between wirings by suppressing recombination of an electromagnetic field from a ground pattern to the other signal line.
A dielectric substrate, an RF signal line that is formed on an upper surface of the dielectric substrate, and transmits an RF (Radio Frequency) signal, and another signal that is formed on the upper surface of the dielectric substrate and is different from the RF signal line. A ground pattern formed on the upper surface of the dielectric substrate, disposed between the RF signal line and the other signal line, and grounded, and a part of the ground pattern on the other signal line side Forms a resistance pattern.
[Selection] Figure 1

Description

  The present invention relates to a microwave device that transmits a microwave signal.

  In recent years, there has been a demand for higher resolution of observation radars, and a wider radar frequency, higher frequency, and higher radar output are desired. The radar includes a transmission / reception module that transmits / receives an RF (Radio Frequency) signal. The transmission / reception module includes a semiconductor device that performs generation, amplification, frequency conversion processing, and the like of a high-frequency signal, a microwave device on which a device such as a capacitor is mounted, and a metal container that houses the semiconductor chip.

  As the radar frequency becomes wider and higher, it is necessary to reduce the size of the metal container of the transmission / reception module. In this case, in the microwave device in the transmission / reception module, the distance between the wires such as the RF signal line and the bias line connected to the device is reduced, the isolation performance between the wires is deteriorated, and it is difficult to ensure the necessary module performance. Become. In addition, as the radar output increases, the gain of the transceiver module inevitably increases. Therefore, in order to ensure the required module performance, high isolation performance is required between the device wirings in the microwave device. It becomes.

  Conventionally, isolation performance between wirings has been improved by providing a ground pattern between signal wirings of a microwave device (see, for example, Patent Document 1).

JP 2011-172173 A

  However, in the conventional microwave device, in addition to the electromagnetic coupling from the RF signal line to the other signal line, the electromagnetic coupling from the ground pattern to the other signal line is further performed by the electromagnetic coupling from the RF signal line to the ground pattern. Recombination of the field occurs. Since this recombination cannot be suppressed, there was a problem that good isolation between wirings could not be secured.

This problem will be further described with reference to FIGS.
FIG. 3 is a diagram illustrating a configuration example of a microwave device as a comparative example. FIG. 4 is a diagram illustrating an analysis result in an electromagnetic field simulator as an electromagnetic field coupling state between the wirings of the comparative example.
In FIG. 3, in the microwave device, an RF signal line 1, the other signal line 2, and a ground pattern 4 are formed on the upper surface of a dielectric substrate 6. The RF signal line 1 transmits a microwave RF signal. The other signal line 2 is a bias line for applying a bias signal, for example. A ground pattern 7 is formed on the lower surface of the dielectric substrate 6. The via hole 3 penetrates the inside of the dielectric substrate 6 and connects between the ground pattern 4 and the ground pattern 7. A ground pattern 4 is disposed between the RF signal line 1 and the other signal line 2. Further, in FIG. 3, a coupling S1 from the RF signal line 1 to the other signal line 2 and a coupling S2 from the RF signal line 1 to the other signal line 2 are illustrated.

  4, a cross-sectional view between each wiring of the RF signal line 1, the other signal line 2, the via hole 3, and the ground pattern 4 is shown, and the state of electromagnetic coupling is indicated by an arrow line. Coupling S1 in FIG. 4 shows the situation of direct electromagnetic coupling from the RF signal line 1 to the other signal line 2. Coupling S2 in FIG. 4 shows the state of electromagnetic coupling to the other signal line 2 with the ground pattern 4 interposed. The ground pattern 4 is grounded by the via hole 3. In FIG. 4, it can be seen that both the coupling S <b> 1 and the coupling S <b> 2 are combined to form a coupling between the wiring of the RF signal line 1 and the other signal line 2.

  The present invention has been made to solve such a problem, and by suppressing recombination of the electromagnetic field from the RF signal line through the ground pattern to the other signal line, the isolation performance between the wirings is improved. The purpose is to improve.

  The microwave device according to the present invention includes a dielectric substrate, an RF signal line formed on the upper surface of the dielectric substrate, for transmitting an RF (Radio Frequency) signal, an upper surface of the dielectric substrate, and an RF signal line. The other signal line formed on the top surface of the dielectric substrate, disposed between the RF signal line and the other signal line, and grounded, and the other signal line in the ground pattern. A part of the side is formed with a resistance pattern.

  According to the present invention, it is possible to suppress recombination of the electromagnetic field through the ground pattern from the RF signal line to the other signal line 2.

1 is a diagram illustrating a configuration of a microwave device according to a first embodiment. In the microwave device according to the first embodiment, it is a diagram showing a state of electromagnetic field coupling between wirings based on an analysis result in an electromagnetic field simulator. It is a figure which shows the structure of the microwave apparatus of a comparative example. It is a figure which shows the analysis result in an electromagnetic field simulator as an electromagnetic field coupling | bonding condition between the wiring of a comparative example.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration of a microwave device according to Embodiment 1 of the present invention.
1, in the microwave device according to the first embodiment, an RF (Radio Frequency) signal line 1, the other signal line 2, and a ground pattern 4 are formed on the upper surface of a dielectric substrate 6. A ground pattern 7 is formed on the lower surface of the dielectric substrate 6 by being connected to the ground. The dielectric substrate 6 is connected to a microwave circuit (not shown) such as an amplifier, a phase shifter, and a frequency mixer. The microwave device according to Embodiment 1 constitutes, for example, a microwave transmission / reception circuit, a transmission / reception module, or an RF module.

The RF signal line 1 is a distributed constant line that transmits an RF signal of a microwave band, a millimeter wave band, or the like to a microwave circuit connected to the dielectric substrate 6. The other signal line 2 is a line that transmits a different signal to the microwave circuit connected to the dielectric substrate 6 so as to avoid interference with the RF signal line 1, and may be a distributed constant line. The other signal line 2 is a bias line for applying a bias signal, for example. FIG. 1 illustrates a state in which the RF signal line 1 and the other signal line 2 are wired in parallel and are spaced apart from each other.
In addition, in the vicinity of a connection point to a microwave circuit (not shown), the interval between the RF signal line 1 and the other signal line 2 may be widened or narrowed, and both may be arranged non-parallel.

  The plurality of via holes 3 penetrate the inside of the dielectric substrate 6 and connect the ground pattern 4 and the ground pattern 7 respectively. A ground pattern 4 is disposed between the RF signal line 1 and the other signal line 2. A part of the ground pattern 4 on the other signal line 2 side forms a resistance pattern 5. The other portion 4b on the RF signal line 1 side of the ground pattern 4 forms a metal conductor film made of gold, silver, copper or the like. The resistance pattern 5 is formed of a thin film resistor, and is disposed in contact with the other portion 4 b in the ground pattern 4. That is, the resistance pattern 5 has a configuration in which a part of the metal conductor film of the ground pattern 4 is replaced with a thin film resistor as compared with FIG. 3 of the comparative example. The upper end of the via hole 3 is connected to the other portion 4 b in the ground pattern 4 at or around the boundary portion between the other portion 4 b and the resistance pattern 5 in the ground pattern 4. A plurality of via holes 3 are arranged along the boundary region.

Next, the operation of the microwave device according to the first embodiment will be described.
In FIG. 1, in the microwave device according to the first embodiment, an RF signal line 1 transmits an RF signal. The other signal line 2 transmits a low-frequency control signal or a bias signal such as a DC signal. Due to the electromagnetic field radiation 7 of the RF signal line 1, an RF signal coupling S 1 is generated from the RF signal line 1 to the other signal line 2.

  In the microwave device according to the first embodiment, the coupling S2 due to electromagnetic field radiation from the ground pattern 4 to the other signal line 2 is suppressed. Thereby, compared with the comparative example of FIG. 3, the coupling S2 from the ground pattern 4 to the other signal line 2 is suppressed.

  Here, the effect of suppressing the coupling S2 by the resistance pattern 5 will be described with reference to the drawings. FIG. 2 is a diagram showing a result of electromagnetic field isolation analysis between the RF signal line 1 and the other signal line 2, and shows an electromagnetic field coupling state between wirings. In FIG. 2, the same reference numerals as those in FIG. 1 are the same. On the other signal line 2 side of the ground pattern 4, a resistance pattern 5 is attached along the edge of the ground pattern 4 in the RF signal transmission direction.

  In FIG. 2, the RF signal coupled from the RF signal line 1 to the ground pattern 4 is suppressed from being coupled to the other signal line 2 due to the effect of the resistance pattern 5. Thereby, the isolation with respect to the electromagnetic coupling between the RF signal line 1 and the other signal line 2 can be enhanced.

  As described above, the microwave device according to the first embodiment is characterized in that the resistance pattern 5 is provided on a part of the ground pattern 4 arranged between the wirings in the microwave device. That is, the dielectric substrate 6, the RF signal line 1 that is formed on the upper surface of the dielectric substrate 6 and transmits an RF signal, and the upper surface of the dielectric substrate 6, and is spaced apart from the RF signal line 1. A ground pattern 4 formed on the upper surface of the other signal line 2 and the dielectric substrate 6, disposed between the RF signal line 1 and the other signal line 2, and grounded. A part of the other signal line 2 side is formed with a resistance pattern 5. In the ground pattern 4, a plurality of via holes 3 may be arranged along the signal transmission direction of the RF signal line 1. The other part of the ground pattern 4 may be made of a metal conductor, and the via hole 3 may be arranged at a boundary part between the other part of the ground pattern 4 and the resistance pattern 5.

  As a result, the RF signal once electromagnetically coupled from the RF signal line 1 to the ground pattern 4 can be prevented from being recoupled to the other signal line 2 (bias line). Isolation characteristics for electromagnetic coupling between the signal lines 2 can be enhanced.

  Further, the effect of the resistance pattern 5 removes unnecessary high frequency leaking from the RF signal line 1 to the other signal line 2 (bias line), thereby improving the isolation characteristics between the wires in the microwave device. As a result, there is an effect of improving signal processing performance such as RF signal passing characteristics and reflection characteristics in the microwave device. As a result, it is possible to contribute to higher output and higher frequency of the microwave device and higher isolation and size reduction of the entire device.

  The resistance pattern 5 can be manufactured using a well-known thin film resistor manufacturing technique and manufacturing process, and it is not always necessary to prepare a new manufacturing process. For this reason, a manufacturing process can be introduced comparatively easily.

  1 RF signal line, 2 other signal line, 3 via hole, 4 ground pattern, 5 resistance pattern, 6 dielectric substrate.

Claims (3)

A dielectric substrate;
An RF signal line that is formed on the top surface of the dielectric substrate and transmits an RF (Radio Frequency) signal;
Formed on the top surface of the dielectric substrate, the other signal line different from the RF signal line;
A ground pattern formed on the top surface of the dielectric substrate, disposed between the RF signal line and the other signal line, and grounded;
With
A microwave device in which a part of the other signal line side in the ground pattern forms a resistance pattern.   The microwave device according to claim 1, wherein the ground pattern has a plurality of via holes arranged along a signal transmission direction of the RF signal line. The other part of the ground pattern is made of a metal conductor,
3. The microwave device according to claim 2, wherein the via hole is arranged at a boundary portion between the other portion of the ground pattern and the resistance pattern.

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