Glenayre Electronics, Inc.

Winegard Company

Kevin Patrick Murphy

Mark A Walker

Thomas L Frederick

Timothy Jay Linderer

David E Jones

Gerald D Deters

A wall plate assembly having a television channel select switch, a channel display, and a signal strength display. A circuit board on the rear of the wall plate includes a television antenna connector, a television output connector, and control electronics. The control electronics displays the selected channel in the channel display, determines the signal strength for the selected channel in any signal on the television antenna connector and displays it in the signal strength display. The control electronics delivers the signal for the selected channel to the television output connector.

Wall plate digital television antenna signal meter and method

A biasing circuit for a power amplifier, for use in a transmitter, that substantially reduces distortion during key-up and thereby reduces key-up time. The power amplifier includes an output transistor and a bias circuit. The bias circuit is applied to all the class AB stages of the power amplifier. The bias circuit provides to the output transistor a first bias level during the preheat period and a second bias level during the transmit period. This first bias level is predetermined to cause the output transistor to reach the steady-state junction temperature achieved by the output transistor during the transmit period (i.e., when transmitting output signals biased with the second bias level). The preheat period ends when this steady-state temperature is reached. Thus, the power amplifier can then transition to a transmit period having already reached the steady-state junction temperature. Because the output transistor is already heated to the steady-state junction temperature, 'thermal' distortion (i.e., the distortion incurred when the output transistor's junction temperature changes while transmitting) is avoided and the key-up time is reduced.

Method and apparatus for reducing key-up distortion by pre-heating

A low-cost microstrip phase detector that is photo-etched onto a circuit board is disclosed. The phase detector is used to detect the phase difference between two high-power radio frequency (RF) signals. One RF signal enters a delay line causing the signal to experience a 180.degree. phase shift. The other RF signal is not phase shifted. Both RF signals are then input into a Wilkinson combiner circuit. The structure of the Wilkinson combiner is such that there is no voltage output from the combiner when the two input signals are exactly 180.degree. out of phase. When the original signals (before the delay line) are in-phase, there is no voltage output from the combiner. However, when the original signals are out-of-phase to begin with, they do not enter the Wilkinson combiner with a 180.degree. phase difference. Instead, the phase difference is greater than or less than 180.degree., depending on whether one input signal leads or lags the other input signal. The signals are not fully dissipated in the balancing resistors, but produce a resultant output voltage from the combiner. This output voltage is proportional to the phase difference and amplitude of the input RF signals. The output of the Wilkinson combiner is connected to a Schottky diode detector circuit that provides a DC output voltage indicative of the phase difference between the input RF signals. The output DC signal is then provided to a digital microcontroller.

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Palmyra, MO, United States of America

Kevin Patrick Murphy