Patent ID: 6668025
Filing Date: 2003-12-23
Classification: H03B,H03D,H04L

Abstract:
A tuning demodulator for digitally modulated RF signals, comprising;(a) an RF input terminal for receiving a digitally modulated RF signal, (b) an RF circuit for receiving said RF signal through said RF input terminal, (c) an I/Q detection circuit for receiving the output signal of said RF circuit, (d) an oscillation circuit for detection for generating an unmodulated RF wave an putting into said I/Q detection circuit, (e) a plurality of I/Q output terminals for issuing a detection output signal of said I/Q detection circuit, (f) at least one of electrical and mechanical signal separating means for suppressing leakage of the unmodulated RF wave from said RF input terminal, and (g) a metallic casing for accommodating (a) to (f), wherein as said signal separating means being an arrangement of the circuits (b) to (d), said RF circuit is arranged so that said oscillation circuit is not adjacent thereto, and hence said RF circuit being physically separated from said oscillation circuit, and invasion of radiated signal from said oscillation circuit into said RF circuit is reduced, and wherein, as said signal separating means, a plane region of a single-layer printed circuit board is divided into two sections, a print pattern of said RF circuit is formed in the surface of one region, a print pattern of said oscillation circuit for detection is formed on a back side of another region, and a plurality of through-holes are provided for electrically shorting between grounding surface of print pattern of said RF circuit and said oscillation circuit for detection.