A mobile wireless communications device, comprising: a housing; an antenna mounted within the housing; radio frequency "RF" circuitry carried within the housing and comprising a transceiver connected to said antenna through which RF communications signals are transmitted and received, and a processor operative with the RF circuitry, wherein said transceiver further comprises an In-phase and Quadrature "I/Q" modulation and power amplification circuit comprising: an In-phase "I" circuit having an In-phase signal input, an In-phase modulator mixer, an In-phase power amplifier circuit that receives the In-phase signal and amplifies the In-phase signal and an In-phase controller connected to the output of the In-phase power amplifier circuit and operative in a closed loop manner with the In-phase power amplifier circuit to control biasing in the In-phase power amplifier circuit and to adjust the amplitude of the In-phase signal; a Quadrature "Q" circuit comprising a Quadrature signal input, a Quadrature modulator mixer, a Quadrature power amplifier circuit that receives the Quadrature signal and amplifies the Quadrature signal and a Quadrature controller connected to the output of the Quadrature power amplifier circuit and operative in a closed loop manner with the Quadrature power amplifier circuit to control biasing in the Quadrature power amplifier circuit and to adjust the amplitude of the Quadrature signal; and a quadrature hybrid power combiner that receives the separately amplified In-phase and Quadrature signals and sums and outputs the signals as a combined I and Q signal for further processing within the RF circuitry, wherein the I and Q signal inputs are isolated from the combined I and Q signal. a housing; an antenna mounted within the housing; radio frequency "RF" circuitry carried within the housing and comprising a transceiver connected to said antenna through which RF communications signals are transmitted and received, and a processor operative with the RF circuitry, wherein said transceiver further comprises an In-phase and Quadrature "I/Q" modulation and power amplification circuit comprising: an In-phase "I" circuit having an In-phase signal input, an In-phase modulator mixer, an In-phase power amplifier circuit that receives the In-phase signal and amplifies the In-phase signal and an In-phase controller connected to the output of the In-phase power amplifier circuit and operative in a closed loop manner with the In-phase power amplifier circuit to control biasing in the In-phase power amplifier circuit and to adjust the amplitude of the In-phase signal; a Quadrature "Q" circuit comprising a Quadrature signal input, a Quadrature modulator mixer, a Quadrature power amplifier circuit that receives the Quadrature signal and amplifies the Quadrature signal and a Quadrature controller connected to the output of the Quadrature power amplifier circuit and operative in a closed loop manner with the Quadrature power amplifier circuit to control biasing in the Quadrature power amplifier circuit and to adjust the amplitude of the Quadrature signal; and a quadrature hybrid power combiner that receives the separately amplified In-phase and Quadrature signals and sums and outputs the signals as a combined I and Q signal for further processing within the RF circuitry, wherein the I and Q signal inputs are isolated from the combined I and Q signal. an In-phase "I" circuit having an In-phase signal input, an In-phase modulator mixer, an In-phase power amplifier circuit that receives the In-phase signal and amplifies the In-phase signal and an In-phase controller connected to the output of the In-phase power amplifier circuit and operative in a closed loop manner with the In-phase power amplifier circuit to control biasing in the In-phase power amplifier circuit and to adjust the amplitude of the In-phase signal; a Quadrature "Q" circuit comprising a Quadrature signal input, a Quadrature modulator mixer, a Quadrature power amplifier circuit that receives the Quadrature signal and amplifies the Quadrature signal and a Quadrature controller connected to the output of the Quadrature power amplifier circuit and operative in a closed loop manner with the Quadrature power amplifier circuit to control biasing in the Quadrature power amplifier circuit and to adjust the amplitude of the Quadrature signal; and a quadrature hybrid power combiner that receives the separately amplified In-phase and Quadrature signals and sums and outputs the signals as a combined I and Q signal for further processing within the RF circuitry, wherein the I and Q signal inputs are isolated from the combined I and Q signal.