RF-Input Outphasing Low-Complexity X-Band Power Amplifier
Abstract
AbstractThe objective of this research is to enable the next generation of wireless transceivers inorder to meet emerging DoD and DoN communications and RADAR needs. The proposed workseeks to develop a GaN power amplifier (PA) that is highly efficient and linear, and that isimplemented with low complexity. Typically, solutions that meet the linearity requirements forcommunications are inherently inefficient due to the operation of the active devices (e.g. linearPAs, Doherty amplifiers), or are highly complex requiring significant baseband processing (e.g.RF PWM techniques, highly digitally-assisted approaches). This project proposes to break thistrend by using efficient switched-mode PAs in a power-combining architecture that providesoverall linearity.The proposed RF-input outphasing (RFIO) power amplifier operates directly on amodulated RF input, but exploits saturated or switched-mode operation of the active devices overa wide dynamic range (as in conventional outphasing transmitters). The approach leveragesmultiple power amplifier elements that are individually highly efficient but nonlinear, andcombines them in an architecture that provides overall linearity. The complexity typicallyassociated with this type of strategy is mitigated by using low-cost, low-component-count passivenetworks that operate directly on a modulated input signal, rather than computation on the inputsignal as in previous realizations of related techniques. In this way, size, weight, and power(SWAP) is reduced while still meeting the required capabilities.This work will demonstrate two-way, X-band RF-input outphasing for the first time,building on a connectorized, discrete-component-based proof-of-concept operating at S band, andon a preliminary MMIC PA design carried out in 0.25um GaN. Advantages of the two-way RFinputoutphasing technique compared to four-way outphasing include greater design freedom inthe RF-domain signal decomposition network, which will allow us to design for high overalllinearity of the system, and leveraging integration of both PAs on a single MMIC to improvematching among the multiple paths. The successful demonstration this RFIO PA will represent a
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 04, 2017
- Source ID
- N000141712104
Entities
People
- Taylor Wallis Barton
Organizations
- Office of Naval Research
- Regents of the University of Colorado
- United States Navy