Abstract: An amplifier bias system and method has only reduced resonances at least throughout the envelope frequency of the signal to be amplified. Thus, the amplifier bias system can provide bias current to the amplifier with minimal voltage variations over the envelope frequency band, especially during signal peaks. For example, the amplifier bias system can be used as an amplifier gate or drain bias network where the amplifier bias system is coupled between the power supply and the gate or drain terminals of the amplifier. The amplifier bias system can include an amplifier bias filter having an impedance which is relatively low at least throughout the envelope frequency of the input signal and relatively high at radio frequency.

Abstract: A variable output power supply for use in a highly efficient linear amplification system includes an envelope detector having at least one input for receiving an input signal to be amplified. The envelope detector generates, as an output, a control signal that is representative of an envelope of the input signal. The variable output power supply further includes a controllable source that is coupled to the envelope detector. The controllable source generates an output voltage and/or current that is responsive to the control signal, such that the output of the variable output power supply dynamically changes as a function of the envelope of the input signal. When employed in a linear amplification system, the variable output power supply provides a supply voltage to a linear amplifier which can be dynamically varied in response to the envelope of the input signal so as to provide a substantially constant voltage supply headroom for the amplifier.

Abstract: In the modular feed for a phased array antenna, the advantages of a series-type feed and a corporate-type feed are combined to increase the system efficiency and the operating bandwidth of the modular feed. Feed modules having a stage of power bifurcation are used to feed array modules having a general series-type feed configuration. The array modules may be interchangeable, and the feed modules may be interchangeable, which decreases production costs and system complexity.

Abstract: A power amplifier system uses adaptive distribution of signals through an amplifier architecture of parallel amplifier stages. For example, the power amplifier system can adjust the operation of individual amplifier stages in the amplifier arrangement, for example to reduce power handling capability of the amplifier stages based on information of the signal to be amplified by the amplifier arrangement, such as the power level. To take advantage of the adjusted operation of the amplifier stages, the power amplifier system uses a variable power divider to reapportion the input signal power among the amplifier stages and at least one variable combiner to adaptively combine amplified signals from the amplifier stages in changing proportions. As such, the power amplifier system is reconfigurable and/or can adapt to changing conditions to provide improved performance and/or efficiency.

Abstract: An amplifier bias system and method has only reduced resonances at least throughout the envelope frequency of the signal to be amplified. Thus, the amplifier bias system can provide bias current to the amplifier with minimal voltage variations over the envelope frequency band, especially during signal peaks. For example, the amplifier bias system can be used as an amplifier gate or drain bias network where the amplifier bias system is coupled between the power supply and the gate or drain terminals of the amplifier. The amplifier bias system can include an amplifier bias filter having an impedance which is relatively low at least throughout the envelope frequency of the input signal and relatively high at radio frequency.

Abstract: A variable output power supply for use in a highly efficient linear amplification system includes an envelope detector having at least one input for receiving an input signal to be amplified. The envelope detector generates, as an output, a control signal that is representative of an envelope of the input signal. The variable output power supply further includes a controllable source that is coupled to the envelope detector. The controllable source generates an output voltage and/or current that is responsive to the control signal, such that the output of the variable output power supply dynamically changes as a function of the envelope of the input signal. When employed in a linear amplification system, the variable output power supply provides a supply voltage to a linear amplifier which can be dynamically varied in response to the envelope of the input signal so as to provide a substantially constant voltage supply headroom for the amplifier.

Abstract: A time slotted system capable of switching between two or more antennas during the guard times of the time slots. Switching between antennas during the guard time of the time slots eliminates any disturbance to the user, since it eliminates any loud noise, or popping that can occur during the switching between antennas. The beamwidth of each of the antennas is narrower than needed to cover a sector of a cell of the system, increasing the size of the cell due to the larger gain of the narrower beamwidth antenna elements. The system also includes a scanning radio for determining the optimal signal amongst the signals received on the antennas, and a switch for coupling the antenna receiving the optimal signal to a receiver system. In one embodiment of the invention the optimal signal is based on the information content of the signal, such as the signal's bit error rate.

Abstract: An antenna array system includes a first array for operating in a transmit mode and a receive mode and a second array spaced apart for operating in the receive mode. A receiver adjusts a receive radiation pattern in the receive mode and provides a control signal for a transmit radiation pattern of the transmit mode.

Abstract: A signal amplification system involves transforming at least one signal to be amplified into at least one transformed signal which is amplified and the resulting amplified transformed signal(s) can be used to produce a version(s) of the at least one original signal. The at least one transformed signal can be produced from the at least one original signal by using the at least one original signal to amplitude and/or angle (phase or frequency) modulate the at least one original signal. After amplification of the at least one transformed signal, the resulting at least one amplified transformed signal is de-modulated to produce a version(s) of the at least one signal. In transforming the at least one original signal to produce the at least one transformed signal, the at least one original signal is transformed into a more desirable form, such as a more power efficient form, for amplification.

Abstract: A wireless transmitter is disclosed that mitigates the 3 MPH effect, which is the phenomenon of poor received signal quality at a wireless receiver because neither transmit power control nor data interleaving are capable of overcoming the effects of Rayleigh fading. Some of the wireless transmitters disclosed mitigate the 3 MPH effect by having the transmit antenna move mechanically, as on a turntable. Other transmitters achieve the same effect by moving the phase center of the transmitted signal between two or more stationary antennas. The phase center of the transmitted signal can be made to move between stationary antennas by electronically manipulating and varying the amount of signal radiated by each antenna. In an illustrative embodiment of the present invention, a signal to be transmitted is switched back and forth between two stationary antennas at a rate that creates virtual motion as observed by the wireless terminal sufficient to remove the wireless terminal from the depths of the 3 MPH effect.