A PHEMT frequency doubling active antenna with BPSK modulation capability

• Published in: IEEE antennas and wireless propagation letters Vol. 3; pp. 310 - 313
• Main Authors: Cabria, L, Garcia, J.A, Malaver, E, Tazon, A
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-01-2004; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Antennas; Binary phase shift keying; Broadband antennas; Carrier frequencies; FETs; Frequency conversion; Frequency doubling; Gates; HEMTs; Low frequencies; Modulation; Modulators; PHEMTs; Radiofrequency identification; Signal generators; Signal processing; Terminals; Transponders
• ISSN: 1536-1225; 1548-5757
• DOI: 10.1109/LAWP.2004.838821

The letter presents a novel frequency doubling active antenna, based on a PHEMT device, with BPSK modulation capability. A dedicated nonlinear transistor characterization reveals the existence of two biasing regions, where the second harmonic could be generated with maximum level and phase opposition. Taking advantage of this issue, a low frequency data signal applied to the gate terminal may be used to create a BPSK modulated signal, centered at twice the carrier frequency. An adequate integration of this modulator in a dual-frequency and dual-polarization slot coupled patch, results in a compact and high performance solution. In order to characterize the integrated active radiating structure, a specific test setup was implemented in an anechoic chamber, reproducing a sort of RFID architecture.