Patent ID: 7693494
Filing Date: 2010-04-06
Classification: H03F,H03G,H04B

Abstract:
1. A pre-power amplifier comprising: A. a load having a load input, a first alternating current ground connection, and a load output, the load including an RF choke connected in series between the load input and the alternating current ground connection, and a DC coupling capacitor having one lead connected to the load input and another lead connected to the load output; B. a switch array having digital inputs and an array output, the switch array including a most significant bit array of CMOS transistors, a least significant bit array of CMOS transistors, and a sigma-delta least significant bit array of CMOS transistors, each transistor having a lead connected to the array output, a lead connected to circuit ground, and an input coupled to the digital inputs; and C. an attenuator having digital pass inputs, digital bypass inputs, an attenuator input connected to the array output, an attenuator output connected to the load input, and a second alternating current ground connection, the attenuator including a pass matrix of CMOS transistors and a bypass matrix of CMOS transistors, each transistor in the pass matrix having a lead connected to the attenuator output, a lead connected to the attenuator input, and a lead coupled to the digital pass inputs, each transistor in the bypass matrix having a lead connected to the attenuator input, a lead connected to the second alternating current ground connection, and a lead coupled to the digital bypass inputs.