RU2189693C1 - High-frequency oscillator stabilized by resonator on surface acoustic waves - Google Patents

Abstract

FIELD: radio engineering. SUBSTANCE: high- frequency oscillator stabilized by resonator on surface acoustic waves has transistor, voltage divider built on two resistors, two blocking capacitors, resonator on surface acoustic waves, inductance coil, variable capacitance of oscillator circuit, resistor and shunting capacitor. EFFECT: widened range of working frequencies, increased stability of generated signal. 1 dwg

Description

 The invention relates to radio engineering and provides an extension of the operating frequency range, increasing the stability of the frequency of the generated signal in the frequency range from 300 to 1200 MHz and allows for frequency modulation of the generated oscillations (in the presence of a modulator), while having a fairly simple design.

 A known generator that performs frequency stabilization, however, it does not allow to obtain stabilized frequencies above 120 MHz and to implement frequency modulation [1].

 The purpose of the invention is the expansion of the operating frequency range, increasing the frequency stability of the generated signal and providing the possibility of its frequency modulation while observing the relatively small size of the generator structure (not more than 10x10 mm).

 The essence of the invention lies in the fact that the generator stabilized by a resonator on surface acoustic waves (SAWs) contains a transistor 1, a voltage divider consisting of resistors 2 and 3, shunt capacitors 4 and 5, a loop inductor 6, a variable capacitor 7, isolation capacitors 8 and 9, a SAW resonator 10 and a resistor 11 (see drawing).

 The voltage divider on resistors 2, 3 and resistor 11 provide a high-frequency generator operating mode for direct current. The generation frequency depends on the tuning frequency of the oscillatory circuit, consisting of an inductor 6 and a variable capacitance 7, and the frequency of the SAW resonator 10.

 At frequencies close to the frequency of the SAW 10 resonator, the impedance of the SAW 10 resonator is minimal and the transfer coefficient of the feedback circuit is sufficient to satisfy the condition of phase and amplitude balance.

 Since the totality of the introduced elements and their relationship to the filing date of the application in the patent and scientific literature are not found, the proposed technical solution corresponds to the "inventive step".

 A comparative analysis with the prototype showed that the new technical solution is characterized by the presence of a positive feedback circuit consisting of isolation capacitors and a surfactant resonator, and corresponds to the "novelty".

 The drawing shows a circuit diagram of a high-frequency generator on a SAW resonator.

 A high-frequency generator based on a SAW resonator operates as follows.

 The generator operation mode by direct current is provided by a voltage divider on resistors 2, 3 and a resistor 11 in the emitter circuit, which, together with capacity 5, performs temperature stabilization. An oscillating circuit containing an inductive coil 6 and a variable capacitance 7 should be able to tune to the middle of the frequency band of the SAW resonator.

 The extension of the range of generated frequencies is achieved by selecting a surfactant resonator and tuning the oscillator circuit of the generator.

 In order to increase the stability of the operating frequency of the generator, the SAW resonator is included in the positive feedback circuit between the collector and the emitter through isolation capacitors.

 To ensure frequency modulation of the generated signal, a modulator is used that controls the position of the operating point of the transistor of the high-frequency generator, thereby changing the capacitance pn of the junction of the transistor, affecting the frequency of the generated signal.

 The signal of the generator can be removed from the collector of the transistor through an isolation capacitor or from part of the turns of the inductance coil of the oscillatory circuit, or through inductive coupling, depending on the required coordination with the subsequent cascade.

Sourse of information
1. Red E. Reference manual on high-frequency circuitry. - M .: Mir, 1990, - p. 157.

Claims (1)

 A high-frequency generator stabilized by a resonator on surface acoustic waves, containing a transistor, the emitter of which is connected to a common bus through a resistor and a shunt capacitor, and a voltage divider on two resistors, one of which is connected between the power bus and the base of the transistor, and the other between the base of the transistor and the common bus, a shunt capacitor connected to the base of the transistor and the common bus, an inductor and a variable capacitance of the oscillating circuit, which are connected between the collector transistor and a power bus, characterized in that a surface acoustic wave (SAW) resonator connected through isolation capacitors is inserted into the positive feedback circuit between the collector and the emitter of the transistor.