1 is an equivalent circuit diagram of a high-frequency oscillator obtained when a conventional high-frequency oscillator is patterned on a semiconductor substrate įIG. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.įIG.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.įurther scope of applicability of the present invention will become apparent from the detailed description given hereinafter.
Therefore, the signal output circuit can have a filter function in addition to an impedance matching function. In addition, by setting the capacitance of the capacitor to be a predetermined value and the shape of the microstrip lines to be a predetermined shape, the value of an S 21 parameter of the signal output circuit reduces at a predetermined frequency. This arrangement is much smaller than arrangements constituted only by microstrip lines such as conventional arrangements.
Dielectric resonator oscillator smith chart generator#
In order to achieve the above objects, a signal output circuit of a high-frequency oscillator according to the present invention comprises a capacitor having one terminal to which a high-frequency signal output from a signal generator is applied, and a microstrip line having one terminal, which is connected to the other terminal of the capacitor, and the other terminal set at a reference potential. It is the second object of the present invention to make it possible to impart a filter function to a signal output circuit in a high-frequency oscillator. It is the first object of the present invention to miniaturize a high-frequency oscillator. Therefore, it is impossible to allow the circuit to have, for example, a filter function of inhibiting transmission of signals having specific signal frequency components. In addition, the signal output circuit having the above conventional arrangement has only a function of obtaining impedance matching. Accordingly, an area on a semiconductor substrate physically occupied by these lines 11 to 14 is increased to result in a large size of the oscillator as a whole. The lines 13 and 14 constitute a capacitor, and a load resistor R L is connected to the line 14.Īs described above, the signal output circuit in this conventional high-frequency oscillator has the microstrip lines 11 to 14 as its constituting elements. A high-frequency signal which appears at the drain of the MESFET Q1 is output through microstrip lines 11 to 14. A dielectric resonator is electromagnetically coupled to microstrip lines 9 and 10 on the gate, and this coupling circuit is expressed as a parallel circuit of L, C, and R. A voltage Vd is applied to the drain of the FET Q1 through microstrip lines 1 to 4, and a voltage Vs is applied to its source through microstrip lines 5 to 8. 1 employs a MESFET (Schottky barrier field-effect transistor) Q1 as an amplifying element. 1.Ī DRO (an oscillator using a dielectric resonator Dielectric Resonator Oscillator) shown in FIG. The arrangement of this high-frequency oscillator is diagrammed in FIG. The present invention relates to a high-frequency oscillator for use in, e.g., a receiving circuit of a satellite communication system.Īs a conventional example of a high-frequency oscillator of this type, there is the one described in a paper titled "AN EASY-TO-USE FET DRO DESIGN PROCEDURE SUITED TO MOST CAD PROGRAMS", 1989 IEEE MTT-S Digest, PP.