SU29877A1 - Cordless telephone transmitter - Google Patents

Description

It is known that oscillatory circuits with quenching attenuation are unfavorable for sideband fingering. In the literature, there are indications on how to tune the device for receiving broadcasting stations, as well as transmitting stations, of a carrier wave, in which this defect is eliminated. The method consists in using the symmetric part of the complex resonance curve of an associated system - an antenna-intermediate circuit.

The literature references refer in one case to a receiving device, and in the other to a transmitter without a carrier wave, built according to well-known, rather complex schemes. It is proposed to use these properties of a complex resonance curve to create a radiotelephone transmitter with reduced carrier amplitude or no carrier wave.

In the inventive radiotelephone transmitter according to the invention, the oscillating circuits of the anode circuit of the main generator and antenna, as well as the anode circuit of one or several pathogens, and the locking circuits are symmetrically configured.

In FIG. Figures 1 and 2 depict diagrams explaining the physical

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the meaning of the phenomena underlying the radiotelephone transmitters built on the principle mentioned above; FIG. 3 is a diagram of the proposed radio telephone transmitter.

As is known, the curve of complex resonance of two oscillatory circuits has two maxima and a minimum between them (giving vertices and a trough), more or less clearly expressed. Typically, the radio transmitter is tuned so that the amplitude of the antenna current is maximum and corresponds to one of the curve's vertices for a given frequency (Fig. 1). When modulating the amplitudes of the currents of both side frequencies, the higher the sound frequency, the more will be reduced.

If we make the product5 (from the capacitance to self-induction of the antenna and the circuits are equal, and adjust the circuits so that the amplitude of the operating current in the antenna with no modulation corresponds to the minimum, i.e. the depression of the curve (Fig. 2) for a given the frequencies from the base will not be attenuated by this tuning for the transmitter without a carrier wave, such a symmetrical tuning seems to have been applied in the Rugby, but with a very complex arrangement of the entire transmitter.

The essence of the invention lies in the development of the principle of symmetrical tuning for the entire transmitting device with a reduced carrier frequency or without a carrier wave, which can greatly simplify and reduce the cost of the transmitting station in relation to the known schemes.

FIG. 3 gives an approximate diagram of the device. The two-stage lamp transmitter is designed so that the product of self-induction and the capacitance of the antenna and the circuit CjLi are equal. The capacitance and self-induction of the oscillating circuit of the exciter and the grid circuit of the main generator are also equal to C iZ-i C2 2Also, the oscillating circuit Csig) tuned in series in the grid circuit of the main generator

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The same can be done for a multistage generator.

If the locking circuits are not very sharply adjusted, then the amplitudes of the carrier frequency are only reduced, which is required for some.

The proposed transmitter can replace balanced oscillators and a dual modulation transmitter.

The subject matter of the invention.

A radiotelephone transmitter, characterized in that the oscillatory circuits of the anode circuit of the main generator and antenna, as well as the anode circuit of one or several pathogens and the locking circuits are symmetrically aligned.

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