General Signal Corporation

Spx Corporation

Brett J Grandchamp

William A DeCormier

Cole Nason Plummer

Richard I Bibber

Charles D Brown

A signal mutiplexer that combines the NTSC and DTV signals of adjacent television channels into a composite signal for transmission on a common transmission line or wave guide. Separate hybrid couplers and band pass filters produce quadrature phase signals that are combined in a signal combiner to produce a pair of quadrature phase multiplexed signals. A notch filter reflects the aural component of the NTSC signal. An output hybrid coupler combines the pair of multiplexed quadrature phase signals with the reflected aural component to produce the composite signal.

Multiplexer for adjacent NTSC and DTV channels

A signal multiplexer for N channel signals of different frequency bands that utilizes only N&plus;1 hybrid couplers and presents a constant impedance to the transmitters that supply the N channel signals. The channel signals are coupled by separate ones of N of the N&plus;1 hybrid couplers to N pairs of matched band pass filters. The outputs of the filters are combined in a signal combiner to form a pair of quadrature phase multiplexed channel signals that are converted to a single multiplexed output signal by the remaining hybrid coupler. A selector mechanism operates to select one of the N inputs for connection to a load for test purposes.

Signal multiplexer and method

A signal multiplexer for N channel signals of different frequency bands that utilizes only N&plus;1 hybrid couplers and presents a constant impedance to the transmitters that supply the N channel signals. The channel signals are coupled by separate ones of N of the N&plus;1 hybrid couplers to N pairs of matched band pass filters. The outputs of the filters are combined in a signal combiner to form a pair of quadrature phase multiplexed channel signals that are converted to a single multiplexed output signal by the remaining hybrid coupler.

A switchable directional coupler in which a three position switch partitions the coupler into three distinct coupling paths among its four ports according to the status of a pair of quadrature phase input signals of amplitudes A and B. In one position with both input signals being active, the output signal has an amplitude of A&plus;B. In a second position with only the input signal of amplitude A being active, the output signal has an amplitude of A. In the third position with only the input signal of amplitude B being active, the output signal has an amplitude of B.

Switching waveguide directional coupler and method

The rigid coaxial transmission line disclosed herein is made up of multiple sections having outer conductors which are joined together at flanges and make up a desired length. Rather than being of equal length, the sections vary in length progressively to prevent the reflections caused by the flanges from accumulating at any frequency within the band at which the transmission line is to operate.

Broadband rigid coaxial transmission line

The coaxial connector disclosed herein accommodates differential expansion between inner and outer conductors in a multi-section run of coaxial transmission line by utilizing a coupler assembly which connects adjacent inner conductors, one of the inner conductors being fixedly connected to the coupler with axial movement being permitted with respect to the other inner conductor. Electrical connection between the coupler and the movable conductor is established at a single axial position by an annular conductive spring member while longitudinal alignment is maintained over the rest of the length of the coupler by insulating rings set into annular grooves. A tubular shield extends from the coupler over the adjacent end of the movable inner conductor without electrical contact. The axial length of the shield is larger than the differential expansion which occurs between inner and outer conductor sections. The shield masks the gap at end of the movable inner conductor which is otherwise variable with differential expansion and thereby minimizes the changes in impedance at the connector.

Growing community of inventors

Cumberland, ME, United States of America

Brett J Grandchamp