Abstract: The present disclosure is directed to a method for calibrating a communications device. The method may include the step of determining a first coefficient based on correction data obtained by the transition from an initial open loop power operation to a power level of a closed loop operation. The method may also include the step of determining a second coefficient of transmitter gain based on the power of one or more transmissions by the communications device. A further step of the method may include determining a strength of a downlink signal received by the communications device from a satellite computed from knowledge of a receiver gain represented by the first coefficient. The method may also include the step of determining a transmit power level for the communications device based on the strength of the downlink signal, the first coefficient, and the second coefficient of transmitter gain.

Abstract: The present disclosure is directed to a method for calibrating a communications device. The method may include the step of determining a first coefficient based on correction data obtained by the transition from an initial open loop power operation to a power level of a closed loop operation. The method may also include the step of determining a second coefficient of transmitter gain based on the power of one or more transmissions by the communications device. A further step of the method may include determining a strength of a downlink signal received by the communications device from a satellite computed from knowledge of a receiver gain represented by the first coefficient. The method may also include the step of determining a transmit power level for the communications device based on the strength of the downlink signal, the first coefficient, and the second coefficient of transmitter gain.

Abstract: The present example provides for adaptive preset gain control. Adaptive Preset gain control may initially utilize calibration look up table values to initially set a power amplifier's gain. Subsequent additional corrections are determined and an adaptation look up table is created and applied to bring operation within tolerance. To maintain the amplifier within tolerance additional corrections may also be determined and added to the Adaptation Look Up table. In an alternative example the Calibration Look Up Table may be omitted, with a first transmission through the power amplifier acting as a training event. The Adaptation Look Up Table, may, by storing the last corrections form a history of prior operation which may be used as built in test to indicate potential system failures.

Abstract: A broadband PIN diode transmit/receive switch. The switch is used for electrically coupling a single antenna alternately to a transmitter and to a receiver. A first PIN diode for switching is connected between the antenna and an output port of a second order network, an input port of the second order network being connected to an output of the transmitter. A tuned tank circuit has an input port connected to the antenna and has an output port connected to an input of the receiver. A second PIN diode for switching is connected from the output port of the tuned tank circuit to an RF ground. A DC source controls the PIN diodes. When both diodes are forward biased the transmitter is connected to the antenna and is provided a good impedance match over a substantial bandwidth, otherwise the receiver is connected to the antenna.

Abstract: A test circuit for use in testing amplifiers in order to check that they are functioning properly at operational power levels. The test circuit includes switching mechanisms which configure the amplifier in feedback mode in order to cause the amplifier to oscillate and a circuitry for measuring the power output of the amplifier during oscillation in order to thereby check that it is properly operational. The circuit may also include a load acting as a fixed attenuator for dissipating the power output of the amplifier and a bandpass filter for selecting an appropriate frequency of oscillation for the amplifier. The circuit may also include a control loop for regulating the amount of feedback and controlling the output power level.

Abstract: There is disclosed a power amplifier which is useful in broadband systems having load impedances with VSWRs up to a range of 2:1 or 2.5:1. The power amplifier is constructed to change its operating conditions to match the load as presented at the output of the amplifier and is particularly useful in systems employing frequency hopping requiring broadband construction. A feedback signal from the output of the amplifier is constructed to provide a signal representing the difference between forward and reflected power which is compared in a multiplier with a signal representing current flow in the power amplifier to produce a control voltage for adjusting the supply voltage of transistors forming the power amplifier. Thereafter, if the load impedance changes, the supply voltage is also changed to minimize dissipation and maintain the efficiency of the amplifier substantially constant.

Abstract: The disclosed RF imbalance detector detects degradation in the performance of either a first or a second radio frequency amplifier and includes a means for monitoring the output of the radio frequency amplifiers. A comparator compares the two monitored outputs and provides a third signal which is converted into a usable signal that represents any RF imbalance between the amplifiers.