U.S. Philips Corporation

Christophe Boyavalle

Patrick Jean

Eric Puechberty

A converter, transmitter and/or receiver for mixing an input signal (I.sub.RF) having a first frequency (RF) with an input signal (I.sub.LO) coming from a local oscillator having a second frequency (LO), and for producing an output signal (O.sub.IF) having an intermediate frequency (IF), with rejection of the harmonics of the second frequency (LO) up to a very high order, for example, higher than the tenth order. The device includes a double balanced ring mixer (17) of field effect transistors (12, 13, 14, 15), having a first and a second pair of input terminals (3, 4; 1, 2) and having a pair of output terminals (5, 6), and a first and a second coupler (18, 19) respectively acting as a phase separator and phase combiner for the input signal (I.sub.RF) having the first frequency (RF) and output signal (O.sub.IF) having the intermediate frequency (IF), connected to the first pair of input terminals (3, 4) and to the pair of output terminals (5, 6) respectively, of the ring mixer (17), and each formed by a first and second identical passive phase shifter circuit (300, 400; 500, 600) including isolated elements, and arranged symmetrically so that the respective impedances on the terminals of the first input pair and the terminals of the output pair of the mixer are identical.

Mixer with cross-connected symmetrical subcircuit couplings

A device includes a passive coupler circuit with lumped elements for coupling a first A.C. signal having a given center frequency (fo) present on a first primary port (P1) to two second A.C. signals phase shifted through 180.degree. present on two secondary ports (P3, P4). The device has a first and a second elementary circuit (B, B') phase shifting through 180.degree. respectively, a differential input terminal (1, 1') and a summation input terminal (2, 2') and first and second output terminals (3, 4; 3', 4'), elementary circuits being connected to each other so that the differential input terminal (1) of the first circuit (B) feeds first primary port (P1), the differential input terminal (1') of the second circuit (B') feeds a second primary port (P'1) connected to ground via an impedance (Zo), the output terminals (3, 4; 4', 3') of the first and second circuits (B, B') are coupled crosswise respectively, and feed said secondary ports (P3, P4), and the summation input terminals (2, 2') are short-circuited.

Growing community of inventors

Brunoy, France

Christophe Boyavalle