GaN Transmitters with 5D Reconfigurability
Abstract
GaN Transmitters with 5D Reconfigurability Abstract - APPROVED FOR PUBLIC RELEASEThe RF group at the University of Colorado at Boulder (Profs. Popovic ~ PI, Psychogiou, Barton and Lasser ~ co-PIs) are proposing a fundamental research effort in TA2.B, Compact, Efficient, Beam-Agile Transmitters. The research is aimed at enabling friendly forces dynamic access to the RF part of the electromagnetic spectrum while denying enemy use, maintaining spectrumdominance through a reconfigurable broadband transmit phased array. We propose to explore a GaN-based front-end transmitter unit element with reconfigurability in terms of: (1) frequency and bandwidth; (2) instantaneous bandwidth and signal modulation; (3) output RF power; (4) beamscanning; and (5) DC power distribution. The five fundamental reconfigurable parameters of the proposed 5D reconfigurable approach are intimately related, as illustrated in Figure 1. 5D control is used to maintain efficiency by distribution of RF and DC power. Distributed scaling across subarrays is enabled by an element-based architecture, to overcome the electronics limitations drivenby tighter prime power budgets and reduced form factors of smaller unmanned system classes.The technical objective of the proposed research is to show improved performance of an EW RF front end, gained from integrated design and associated tradeoffs in a 5D reconfigurable architecture. We propose a scalable solution that enables high output power of 5kW continuous wave (CW) over an octave (6-12GHz) with electronic beam steering/forming and an output stageaverage efficiency of 40% for multiple beams and >50% peak, in a small form factor suitable for future classes of unmanned systems with tighter prime power budget.At the unit element level, the scaling is accomplished in: (1) Power scaling through peripheryscaling and bias-control boost power PA modes; (2) Carrier bandwidth and number of bands through reconfigurable filter networks and PA-filter co-design; (3) Instantaneous bandwidth (IBW) and number of signals through digital control design synchronized with dynamic power modulation. The efficiency is maintained through dynamic supplies and co-design across systemand component levels.At the sub-array and array level, scaling is enabled by unit element design: (a) Number of beams and beamwidth scaling, through phase control, and distribution of dynamic power supplies; (b) effective isotropic radiated power (EIRP) is scaled through multiple levels of power combining (device-level, on-chip and off-chip circuit, and spatial), number of subarrays, array reconfigurationfor sidelobe control, etc.The efficiency at the element level is maintained through dynamic supplies and co-design across system and component levels. Based on our current research approaches for octave band PA design, we will work with Qorvo~s 250nm and 150nm process to cover broader bands either in a single or dual-chip configuration, and by die-level and circuit-level combining to enable a nominalpeak CW output power from a single chip of 20W with peak efficiency of 50% over an octave bandwidth. This will lead to improved average power handling of 10 dB greater than current state of art for nearly CW operation with all associated electronics that fit within a volume of 27,000cm3 (1ft3) and an antenna aperture of about 42cm x 42cm. For a spacing of 2cm that is <~/2 at the lowest frequency (~=5cm), this implies on the order of 350 elements, with a total single-beamEIRP=4MW.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 15, 2019
- Source ID
- N000141912487
Entities
People
- Zoya Popovic
Organizations
- Office of Naval Research
- Regents of the University of Colorado
- United States Navy