JPS6288402A - Monolithic microwave oscillator - Google Patents

Abstract

PURPOSE:To attain the miniaturization and mass-production of the entire IC by applying N-branch in the monolithic microwave IC by N-branch subjected to impedance matching. CONSTITUTION:The impedance Zd of a microwave oscillation circuit 10 at oscillation when viewed from a drain terminal 12 toward an FET 1 is expressed as Zd=(-R-jX). On the other hand, the impedance ZL when viewed from an input terminal 13 of N-set of transmission lines toward a load is 50OMEGA/N. Since the oscillating condition is satisfied and the power fed to the impedance ZL is maximized, the sum of the impedances Zc and Zd viewed from the drain terminal 12 is to be zero, but the condition is attained by the proper design of matching circuits 4a, 4b. Through the constitution above, the N distribution circuits are executed by N ranch circuits, and the circuit is simplified in this way, then the miniaturization and mass-production of the monolithic IC are realized.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a monolink microwave oscillator comprising a monolithic microwave IC. In order to drive the oscillator, it is necessary to distribute the output power of the oscillator.

Wilkinson type power dividers are widely used for this purpose, but in order to achieve stiffness with a planar circuit, a second
The configuration shown in the figure has been used conventionally.

In the figure, in order to divide the output power of the oscillator 10 into N equal parts, a Wilkinson type divider consisting of two 1/4 wavelength transmission lines 21 and 22 and one isolating resistor 23 is used (N-1). It was necessary. In the Wilkinson type distributor, isolation can be achieved by the resistor 23 between the two output terminals.

(Problems to be Solved by the Invention) In this conventional configuration, as can be seen from FIG. 2, the size of the circuit increases as the distribution number N increases. Furthermore, the presence of the isolating resistor used in the distributor circuit reduces mask design man-hours.

This causes an increase in the number of man-hours required for prototyping. Therefore, in such a conventional configuration, the entire monolithic IC is miniaturized.

The problem was that it was not suitable for mass production.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems by providing a monolithic microwave oscillator which is small in size and has multiple output terminals capable of producing one output.

(Means for Solving the Problems) The configuration of the monolithic microwave oscillator of the present invention is such that an inductor and a yapacitor are connected to an FET, and each is connected to a load having a predetermined impedance via a transmission line having a predetermined characteristic impedance. and an output circuit.

(Function) According to the electronic circuit element having the structure of the present invention, when a bias voltage is applied between the drain and source and between the gate and source of the FET, it oscillates at a microwave frequency, and each output terminal has a filthy amplitude micro wave. It can output wave signals.

(Example) Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram of a monolithic microwave oscillator having N output terminals, which is an embodiment of the present invention. In the figure, the oscillator is FET1. Inductor 2. Capacitor 31 matching circuit 4a, 4b and N arbitrary length 50
0 transmission lines 5,6°...17,8.

The operating principle of this oscillator is explained as follows.

Output terminals 51.61...71.8 of each transmission line 5-8
1 is connected to a load 56 of 50Ω each, positive feedback is applied by the capacitor 3, and the microwave oscillation circuit 10 oscillates at a frequency determined by the values of the capacitor 3 and the inductor 2.

At this time, the impedance Zd when looking at the FET l from the drain terminal 12 is expressed as (-R, -JX). on the other hand,
The impedance Zt when looking at the load from the input terminal 13 of the N transmission lines is ZL = 50 Ω/N since it consists of N 500 loads with impedances 5 to 8 connected in parallel under equal constraints. .

In order to simultaneously satisfy the oscillation conditions and maximize the power supplied to ZL, the sum of impedances Zc and Zd viewed from the drain terminal 12 to the load must become zero. These conditions are satisfied by appropriate design of matching circuits 4a, 4b.

As explained above, it can be seen that the signals output to each of the 500 transmission lines have a poor amplitude, and the output power of the oscillator is divided into N equal parts. Isolation between the output terminals may not be affected, but as long as the loads are matched, it will not affect the operation of the circuit.

(Effects of the Invention) In this way, in the oscillator of the present invention, signals of the desired phase and the same output level can be extracted from N output terminals (N is the number of distribution), so the shape is large, the mask design man-hours are required, and the trial production]
This eliminates the need for a Wilkinson-type power divider that requires a lot of man-hours, and the monolithic IC has the effect of making it possible to downsize and reduce production to 1.

[Brief explanation of drawings]

FIG. 1 is a plan view of a monolithic microwave oscillator having multiple output terminals according to an embodiment of the present invention, and FIG. 2 is a plan view showing a conventional oscillator with a power divider. 1...FET, 2...Inductor, 3
...Positive feedback capacitor, 4a, 4b...
...Matching circuit, 5゜6,...,7.8...Transmission line with characteristic impedance 50Ω, 10...
Oscillation circuit, 51.61...71°81...Output terminal, 12...Drain terminal, 13...
...Transmission line input terminal, 21.22...1/
4-wavelength transmission line, 23...isolation resistance, 56j...50Ω load resistance. 61i 2 equal parts I4 divisible 1 flower 2 figure

Claims (1)

[Claims] A microwave oscillation circuit in which an inductor and a capacitor are connected to an FET, a matching circuit connected to the output of this oscillation circuit, and the output from this matching circuit is branched into N lines (N is a natural number) and transmitted through a transmission line with a predetermined characteristic impedance. A monolithic microwave oscillator comprising a load having a predetermined impedance and an output circuit connected to each load.