Series anti-parallel diode linearizer for class-B power amplifiers with a gain expansion

A Series Anti-Parallel Diode Linearizer (SAPDL) for class-B power amplifiers with a gain expansion has been proposed. SAPDL has the characteristic whose gain is decreased in the middle power region and is increased in the saturated region. In this paper, the operation principle of SAPDL is made clear. SAPDL is applied for a class- B UHF-band power amplifier with a gain expansion. An improvement of Adjacent Channel leakage Power Ratio (ACPR) of 4 dB and Power Added Efficiency (PAE) of 6 % has been achieved for the OFDM signal of the 6MHz bandwidth.