JPH018001Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a mixer consisting of a waveguide and a strip substrate, etc., and uses a capacitive strip to cancel out the inductance component due to the lead wire of the diode mounted inside the waveguide. This paper proposes a mixer with the aim of making it possible to

First, a conventional mixer will be briefly explained.

FIG. 1 shows an example of a typical configuration of a conventional mixer composed of a waveguide, a strip substrate, and the like.

The mixer shown in FIG. 1 consists of a waveguide 1, a diode 2 provided inside the waveguide 1, a strip line 3, a ground pattern 4, and a strip substrate 5 on the surface of which is formed. It consists of

Now, a frequency _RF signal is input from RF port A.
When a local oscillator signal with frequency _LO is input from LO port B, diode 2 mixes the above _RF and _LO , and the difference frequency is an intermediate frequency signal, _IF = | _RF −
_LO | passes through the strip line 3 and is output to the IF port C. The equivalent circuit around diode 2 in this mixer configuration is shown in FIG.

Rd+jXd in FIG. 2 is the impedance 7 between the terminals of the diode 2. Also, jwL is a series inductance component 6 between the waveguide and the strip conversion portion, which is generated because the lead wire of the diode 2 enters the waveguide.

However, in the conventional mixer configuration shown in Figure 1, when the waveguide height is higher than the width between the diode electrodes, the length of the diode lead wire inside the waveguide becomes longer, and the series inductance component also increases, resulting in a wide band The drawback was that consistency could not be achieved.

The purpose of this invention is to enable broadband matching by eliminating the influence of inductance components caused by conventional diode lead wires.

An embodiment of this invention will be described below with reference to the drawings.

FIG. 3 is a diagram showing the diode portion of the mixer, which is a feature of this invention.

As shown in FIG. 3, this mixer consists of a waveguide 1,
It is composed of a diode 2, a strip line 3, a ground pattern 4, a strip substrate 5, and a capacitive strip 8. Strip line 3 mounted on a strip board as shown in Figure 3
A portion of the ground pattern 4 enters the waveguide 1 and is connected to the diode 2, and a portion of the strip line 3 and the ground pattern 4 form a capacitive strip 8. Furthermore, the inductance component due to the lead wire portion of the diode 2 is eliminated by the capacitive strip 8. FIG. 4 shows an equivalent circuit around the diode in this invention. According to this, the reactance component 6 due to the lead wire in the equivalent circuit of the conventional configuration shown in FIG. 2 is compensated, and a slight capacitance component 9 is added, but the width and length of the capacitive strip can be adjusted. This allows the capacitance component to be minimized.

In this way, the inductance component 6 of the lead wire of the diode that enters the waveguide has traditionally prevented the widening of the mixer's bandwidth. It becomes possible to compensate for the inductance component 6 of the mixer and to widen the band of the mixer.

[Brief explanation of drawings]

Figure 1 shows the diode part of a mixer consisting of a conventional waveguide and a strip substrate;
The figure shows an equivalent circuit of the diode part of the conventional mixer mentioned above, Figure 3 shows the diode part of the mixer consisting of a waveguide and a strip substrate, which is a feature of this invention, and Figure 4 shows the equivalent circuit of the diode part of the above-mentioned conventional mixer. 3 is a diagram showing an equivalent circuit of FIG. 3, which is a feature of this invention, in which 1 is a waveguide, 2 is a diode, 3 is a strip line,
4 is a ground pattern, 5 is a strip board, 6 is an inductance component due to a lead wire, 7 is an impedance of a diode, 8 is a capacitive strip, and 9 is an equivalent capacitance component due to the capacitive strip. In addition, the same or equivalent parts in the figures are indicated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] A waveguide, a diode included in the waveguide, and a strip substrate provided with a strip line and a ground pattern that are provided to intersect with the waveguide and connect to the lead wire portion of the diode. In the mixer, a part of the strip line and the ground pattern are overlapped with the lead line part of the diode in the waveguide, and the strip line and the ground pattern are widened to generate capacitance, and the capacitance component causes the diode to A mixer characterized in that it is configured to cancel an intance component due to a lead wire portion.