RF selection switch for multiple antenna input

Abstract

RF switches are known from the art for selecting an RF signal from a multiple of inputs. For instance a TV-tuner and TV-Front-end can have two or more antenna inputs but are implemented with a relative bad cost performance. The present invention relates to an RF selection switch circuit (200). The switch comprises a first switch (202), a second switch (204) with both an RF input port and a common RF output port a control signal circuitry (206). In a preferred embodiment the switches comprise pin-diodes. The RF output port comprises two transistors (T1, T2), one of which at a time can put the non-selected switch to a low-impedance level in order to minimize signal leakage the common output port.

Description

technical field [0001] The invention relates to an RF (Radio Frequency) input circuit equipped with an RF switch having a plurality of inputs and at least one output, the RF input circuit having good isolation between the inputs, good sensitivity and low cost . [0002] The invention particularly relates to TV tuners and TV front ends having two or more antenna inputs, eg one for cable TV and one for terrestrial TV. Background technique [0003] RF switches are known in the art for selecting RF signals from multiple inputs. Examples include TV tuners and TV heads with two or more antenna inputs, one for cable TV and one for terrestrial TV, or two cable TV inputs (A / B) . [0004] The two main solutions of RF switches known today are electro-mechanical switches and electronic switches. Compared to electronic switches, electro-mechanical switches are bulky, relatively expensive (BOM) and have higher voltages and currents. In an electronic solution, if good isolation is req...

AI Technical Summary

Problems solved by technology

[0011] To meet the above requirements, relatively expensive and complex RF switches have been developed in the prior art

Images