Hans Kriedt

High Performance FM-IF IC for Systems with Search Tuning Stop and Multipath Interference Detection

Mobile antennas, located close to the ground, e.g. receivers in vehicles, are subject to continuously changing field strength levels. Through the effects of scattering and reflection, partial waves are superimposed on the direct signal depending on time and location and lead to interferences due to multipath (MP) reception.

Modular Video IF Concept

We have developed a new family of monolithic wide-band video IF-amplifiers, based on a modular design concept. This allows both short realisation times for different requirements and optimal chip sizes. The pinning provides optimal decoupling and permits the use of one print layout for the whole family.

A World Standard Video And Sound IF IC

An IC for wordwide video and sound IF applications is described below. It consists of: 1.) A video IF for positive and negative modulation with FPLL carrier regeneration followed by a video switch. A separate video output after the demodulator permits the installation of a sound trap at the input of the video switch. An AFC signal is derived from the VCO tuning voltage 2.) A sound IF for AM and FM sound transmission using a multi-standard FM IF converter. 3.) A dual FM sound IF for A2 stereo I dual sound transmission with A,M/FM audio switch at the audio output 1. 4.) An IZC bus interface controlling all switching functions and the three ports as well as for reading out the TV identification and the AFC data.

An Integrated Circuit for Fast Automatic Alignment of TV Tuners

Current TV tuner concepts use a two or three- stage preselection for each tuner section. The present solution requires a very long time of about 5 minutes to perform the two-frequency tracking procedure to achieve an optimum synchronism of all tuned r.f. circuits to the oscillator circuit. This expenditure of time can be partly reduced in a first step to a value of approximatly 3¿minutes by using surface mounted components. However, expensive discrete components such as matched tuner diodes and capacitors are required.