Theory and Design of Class-J Power Amplifiers With Dynamic Load Modulation
Artikel i vetenskaplig tidskrift, 2012

A theory for class-J microwave amplifier operation as a function of drive level and fundamental load impedance is derived. Calculations show that, under appropriate operating conditions, it is sufficient to modulate the transistor load reactance to enable high-efficiency operation (>70%) over a large output power dynamic range (>10 dB) with high transistor power utilization. Such dynamic load modulation (DLM) networks are an ideal application of continuously tunable varactor technologies. Multiharmonic load–pull measurements are performed on a GaN HEMT and experimentally verify the theory of operation. A demonstrator amplifier using an SiC varactor technology is then designed and characterized by static measurements. The amplifier has a peak power of 38 dBm at 2.08 GHz and maintains efficiencies above 45% over 8 dB of power dynamic range. An analysis of the load network losses is performed to show the potential of the class-J DLM transmitter concept.

Energy efficiency

varactors

gallium nitride (GaN)

silicon–carbide (SiC)

power amplifiers

Författare

Christer Andersson

GigaHertz Centrum

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

David Gustafsson

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

Koji Yamanaka

Mitsubishi Electric Corporation

Eigo Kuwata

Mitsubishi Electric Corporation

Hiroshi Otsuka

Mitsubishi Electric Corporation

Masatoshi Nakayama

Mitsubishi Electric Corporation

Yoshihito Hirano

Mitsubishi Electric Corporation

Iltcho Angelov

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

GigaHertz Centrum

Christian Fager

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

GigaHertz Centrum

Niklas Rorsman

Chalmers, Mikroteknologi och nanovetenskap (MC2), Mikrovågselektronik

IEEE Transactions on Microwave Theory and Techniques

0018-9480 (ISSN)

Vol. 60 3778-3786

Styrkeområden

Informations- och kommunikationsteknik

Drivkrafter

Hållbar utveckling

Ämneskategorier

Telekommunikation

Kommunikationssystem

Elektroteknik och elektronik

Infrastruktur

Nanotekniklaboratoriet

DOI

10.1109/TMTT.2012.2221140