Siemens Aktiengesellschaft

Anton Sunkler

Heinz Merkle

Gerhard Gruenberger

A circuit arrangement for the production of a control signal, in particular a level regulation signal, in a receiving channel which is subject to interference, forms an amplitude-dependent control signal from the phase coded input signal. In the receiving channel a frequency regulating circuit has an oscillator which is synchronized by means of the received signal and the received signal is superheterodyned with the output signal of the oscillator in one mixer, directly, and delayed by 90.degree. in another mixer. The mixed products are then fed through low-pass filters to obtain signals which indicate the frequency shift between the input signal frequency and the oscillator frequency, which signals are converted in a third mixer and serve for tuning the oscillator. The output signals obtained from the outputs of the two first-mentioned mixers, after being fed through low-pass filters, are squared and combined in a difference stage. The result is again passed through a low-pass filter and squared again before being fed to an addition stage. One input of the addition stage is obtained from the output signal of the third mixer, after squaring, and an amplitude correction stage is provided in front of another input of the addition stage to effect cancellation of the signal components arising from phase errors of the frequency regulating circuit and from the noise components in the useful signal. The interference-free output obtained is used as the control signal.

Circuit arrangement for the production of a control signal in a

A transistor oscillator for microwave frequency ranges has a transistor with interelectrode capacitances used for feedback. A series connection of a voltage controlled variable capacitor and line element are connected to the collector of the transistor as a frequency determining element. A line element is connected to the base for feedback and bias means are connected to the base and emitter through high frequency choking means constructed of two quarter wavelength line elements, one of which is arranged in no-load fashion. An attenuation network for frequency selection action is connected to the collector feedback path to dampen the oscillating circuit and prevent frequency jumping of the oscillator outside of the band intended for useful operation.

Microwave transistor oscillator for wide band frequency tuning

A transistor oscillator for the microwave band, utilizing CLAPP-circuit configuration, in which a small additional capacitance is connected in series with collector-base capacitance and is disposed between the base and ground. The additional capacitance may be in the form of a trimming capacitor, varactor elements or a line section having a length of less than .lambda./4, and where strip line technology is employed high frequency filter chokes may be employed in the form of line sections, each of a length of .lambda./4 whose ends are short circuited over blocking capacitors.

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Munich, Germany

Anton Sunkler