An amplifying apparatus for linearly amplifying a desired signal using a pair of coupled non-linear amplifiers is disclosed. The amplifying apparatus comprises a limiter for separating amplitude variations from the desired signal and producing a constant amplitude signal bearing the phase of the desired signal and an amplitude related signal. In addition, a drive signal generater produces two drive signals each dependent on the constant amplitude signal and the amplitude related signal such that each drive signal depends on the phase of the desired signal and such that the sum of the squares of the amplitudes of the drive signals is constant. Finally, a coupler couples the two drive signals to produce two constant amplitude signals for driving the pair of non-linear power amplifiers and for coupling the outputs of the power amplifiers to produce two amplified output signals, one of which is the linearly amplified desired signal and the other of which is a waste energy signal.

Waste energy control and management in power amplifiers

A method of determining one or more attributes of an antenna beam based on measuring phase and/or amplitude differences at different points in a feed network. Amplitude and/or phase are measured by a probe ( 13 ) at an input to a differential variable element ( 7, 8, 9 ) and by a probe ( 14 ) at fewer than all of the outputs of the differential variable element. By using lookup tables based on actual measurements of antenna beam attributes for phase and/or amplitude differences at different points in a feed network computation may be simplified. The method enables a relatively inexpensive control circuit to be employed while providing accurate measurement of antenna beam attributes.

Array antenna and a method of determining an antenna beam attribute

An improved method and apparatus for using parallel amplifiers to efficiently amplify an information signal are disclosed. The improved apparatus utilizes digital signal manipulation techniques in optimizing the phase of the upconverted input signals provided to each of the parallel amplifiers. The phase and amplitude of the input signals are adjusted such that the power measured at the output of a combiner (402) is maximized as compared to the sum of the power of combiner (120) input signals.

Parallel amplifier architecture using digital phase control techniques

An RF power amplifier system comprises an amplitude control loop and a phase control loop. The amplitude control loop adjusts the supply voltage to the power amplifier based upon the amplitude correction signal indicating the amplitude difference between the amplitude of the input signal and an attenuated amplitude of the output signal. The phase control loop adjusts the phase of the input signal based upon a phase error signal indicating a phase difference between phases of the input signal and the output signal. The phase control loop may comprise one or more variable phase delays introducing a relative phase delay to allow the phase differences between the input and output signals of the PA circuit to be within a range compatible with a phase comparator generating the phase error signal, and a low frequency blocking module that removes the larger extent, lower frequency components of the phase error signal.

RF power amplifier controller circuit including calibrated phase control loop

Optimization methods via various circuital arrangements for amplifier with variable supply power are presented. In one embodiment, a switch can be controlled to include or exclude a feedback network in a feedback path to the amplifier to adjust a response of the amplifier dependent on a region of operation of the amplifier arrangement (e.g. linear region or compression region).

Optimization methods for amplifier with variable supply power

RF power is sampled and measured at the input and output of a solid state power amplifier using directional couplers and matched square law detectors. Outputs from the detectors are applied to differential inputs of a DC operational amplifier. Outputs from the detectors are compared and filtered in the operational amplifier and the resulting difference signal is applied to a control input on a switching type power supply. The power supply converts a DC input voltage to the various positive and negative voltages required to operate the RF devices in the solid state power amplifier. When the control loop is closed, the supply voltage varies to maintain a constant operating point resulting in constant gain, efficiency, and linearity for the overall solid state power amplifier despite variations in signal levels and signal composition. In another embodiment, the solid state power amplifier has a series of single-ended low power amplifiers terminating in an output high power module. In the output module, one medium power device acts as a driver stage for four high power devices connected in parallel. The output stages are hybrid coupled, and isolators before and after these hybrid coupled output stages isolate the driver from the final amplifiers and protect the output devices from reflected signals. A dynamically controlled PIN diode variable attenuator at the amplifier input allows the operating point of the amplifier to be selected and adjusted while the closed loop function is in operation. A hybrid matrix power amplifier system is also disclosed.

Arnold L Berman

Papers

Solid state power amplifier with dynamically adjusted operating point