Novel architectures for high-efficiency amplifiers for wireless applications

Abstract

This paper presents three novel architectures for high-efficiency amplifiers relying on new harmonic-tuning techniques. These methods yield high-efficiency power amplifiers and reduce unwanted harmonic radiation from the transmitter front end. The first method uses the active integrated-antenna approach to perform harmonic tuning. The second method uses a nontraditional periodic microstrip filter, which allows broadband harmonic tuning. Finally, the third method combines the previous two approaches. Each technique is illustrated by a design example of a power amplifier integrated with an antenna. Guidelines for choosing the appropriate antenna structure and for designing the periodic structures are also presented. Another design issue is inclusion of the antenna and/or periodic structures into the amplifier simulation. To do this, a hybrid approach combining the finite-difference time-domain (FDTD) analysis and harmonic-balance simulation is employed.

Wideband antenna with wideband harmonic suppression using non-uniform defected ground structure

“…These antennas suffer from high levels of harmonic radiation, which may degrade the system performance by increasing the electromagnetic interferences [1]. In conventional systems, additional components such as filters are used to suppress harmonic radiation.…”

FWCIP method for PGB planar structures

“…This structure presents very interesting rejection proprieties [4,5], and it was used to achieve harmonic matching in class A and class B amplifiers. This structure was also improved by using a 2D periodic structure, which was constituted of holes periodically drilled in the ground plane [6][7][8].…”

“…Recently, PBG structures have been achieved in planar circuits [4][5][6][7][8], in particular a microstrip line under a honeycomb mesh, which is constituted of drilled dielectric. This structure presents very interesting rejection proprieties [4,5], and it was used to achieve harmonic matching in class A and class B amplifiers.…”

High-efficiency push-pull power amplifier integrated with quasi-Yagi antenna

“…As shown in (1) and (2), the output currents consist of antiphase fundamental terms and in-phase higher harmonic components. In the traditional microwave-frequency push-pull PA, the two FET devices are typically combined using a broad-band 180 hybrid or a balun.…”