JPS6122344Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a microwave mixer that has good characteristics over an extremely wide band.

A mixer operating in a microwave band using a ring modulator using four nonlinear elements is constructed as shown in the principle diagram shown in FIG. In FIG. 1, the microwave signal input is applied from terminal R to the ring modulator RMD via the balanced-to-unbalanced converter BLN,
On the other hand, a local oscillation signal input is applied from terminal L to RMD via another BLN. RMD generates a difference frequency signal between input signals R and L, and takes it out from the intermediate frequency output I terminal. The part centered on the modulator RMD for obtaining intermediate frequency output in this way is commonly called a mixer. C indicates the DC interrupting capacity between the mixer and each signal input terminal. A conventional example of realizing the configuration shown in Fig. 1 is a dielectric substrate DEB as shown in Fig. 2.
Thin conductor plates PL are provided in parallel on each of the upper and lower principal surfaces to form a stripline STL, and the lower conductor in the figure is wide near the signal application terminals at both ends to form a balanced-unbalanced converter BLN. ing.
CNT indicates a connector terminal for connecting to a signal source. The ring modulator RMD is extremely large when using a quad diode package and has a three-dimensional structure, so care must be taken when connecting each terminal to avoid unnecessary crossing in different directions. There is. In addition, even if it is a single package, the length of the connecting wires that connect to the stripline is usually several mm or more, and they are close to each other and extend appropriately in each direction, so they are used in bands of several GHz or more. When doing so, the arrangement of the connecting wires causes deterioration of signal conversion characteristics, and furthermore, it becomes difficult to use in high frequency bands, which limits the production volume and has the drawback that costs cannot be reduced.

An object of the present invention is to improve the above-mentioned drawbacks and to provide a microwave mixer which has a relatively simple structure and operates with good characteristics over an extremely wide band.

Embodiments of the present invention shown in the drawings will be described below. FIG. 3 is a perspective view showing an embodiment of the present invention.
A thin conductor plate PL that forms strip lines STL on each of the upper and lower surfaces of the dielectric substrate DEB, such as sapphire.
1 to PL4 are provided, PL1 and PL2 and PL3 and PL
4 and is opposed to each other with a gap in the center of the board DEB. Two through holes THL are provided in the spaced portion passing through the substrate DEB, and in the drawing of FIG. 3, the inside is filled with metal to form a conductive wire. The nonlinear element is constructed as shown in FIG. 4, a partially enlarged sectional view. Taking thin conductor plates PL2PL4 that form a stripline as an example, each conductor plate
Silicon oxide is applied sequentially from PL2 and PL4 in each direction upward and downward.
An insulating layer of Sio ₂ , a vapor-deposited metal film MF, and a diode chip DT (for example, a shot barrier diode chip) are provided approximately symmetrically with respect to the substrate DEB. Next, the diode chips DT of the opposing thin conductor plates PL1 and PL3 are connected through the metal of the through hole THL to form a ring modulator. Alternatively, a conducting wire passing through the through hole THL may be provided to connect the diode chips DT to each other. Here, thin conductor plate PL
Since a capacitor is formed between 2 or PL4 and the metal film MF using the insulating layer as a dielectric, this capacitor can be effectively used as a DC blocking capacitor.

FIG. 5 is a top view of FIG. 3 and shows what is provided on the substrate including the high frequency choke coil RFC of the intermediate frequency output stage. Therefore through hole
There are four THLs available. Figure 5 shows a size comparison example when a 0.3 mm square diode chip is arranged on a board with a length of 3 mm and a width of 15 mm.Since the diode chips are arranged symmetrically, the connecting wires are fused to each other. Since the length can be made extremely short, around 1 mm, it has the great effect of minimizing deterioration in conversion efficiency over an extremely wide band up to the 20 GHz band, as shown in the characteristic diagram shown in Figure 4.

Further, according to the present invention, since the structure is simple, patterns can be formed in the same manner as in semiconductor manufacturing processes, making it possible to produce small and lightweight products.

Furthermore, since it can be used over a wide band, it can be mass produced, resulting in a significant reduction in unit cost. Furthermore, since the characteristics are made uniform, reliability is improved.

[Brief explanation of the drawing]

FIG. 1 is a principle diagram of a microwave mixer using a ring modulator, FIG. 2 is a perspective view of a conventional example that realizes the configuration of FIG. 1, and FIG. 3 is a perspective view of an embodiment of the present invention.
4 is a partially enlarged sectional view of FIG. 3, FIG. 5 is a top view of FIG. 3, and FIG. 6 is a diagram showing the operating characteristics of FIG. 3. R...Microwave input terminal, L...Local oscillation signal input terminal, I...Intermediate frequency signal output terminal, C...
...DC blocking capacity, BLN...balanced-unbalanced converter, RMD...ring modulator, STL...stripline, THL...through hole, DT...diode chip, MF...deposited metal film, DEB ...Dielectric substrate, RFC...High frequency chiyoke coil.

Claims (1)

[Claims for Utility Model Registration] 1. Using four nonlinear elements connected in a ring shape on a dielectric substrate with strip lines formed on each upper and lower surface, a high frequency reception input and a local oscillator output are applied, and the intermediate In a mixer for obtaining a frequency signal, the stripline on each of the upper and lower sides is cut, and a plurality of through holes are provided in the middle part to pass through the dielectric substrate, and the conductor facing part of the stripline is provided with a plurality of through holes on each of the upper and lower sides of the dielectric substrate. A microwave mixer characterized in that a total of four chip-shaped nonlinear elements are installed in a point-symmetrical manner, and each nonlinear element is connected to each other via a through hole to form a ring modulator. 2. A metal thin film is provided on the conductor facing part of the strip line with an insulating layer interposed therebetween, and a nonlinear element is provided on the outside of the metal thin film.
2. The microwave mixer according to claim 1, wherein the insulating layer is a dielectric material and is used as a direct current blocking capacitor between the mixer and each signal input terminal.