A Doherty amplifier for TD-SCDMA base station applications based on a single packaged dual-path integrated LDMOS power transistor

A Doherty power amplifier designed for TD-SCDMA base station applications using a dual path two-stage IC with LDMOS technology has been demonstrated with excellent performance. The IC was fabricated using Freescale HV7IC technology and designed to cover both the 1.88–1.92 GHz and the 2.01–2.025 GHz TD-SCDMA bands. It delivers 70 W P3dB output power under CW signal. At 40 dBm output power or 8.5 dB output back off at P3dB gain compression, the Doherty power amplifier exhibits 30.2 dB power gain, 35.4% power added efficiency and −32.5 dBc raw ACPR under 7.1 dB PAR TD-SCDMA modulation in the 2.01–2.025 GHz band. A −52.8 dBc ACPR was obtained after digital pre-distortion. This is the first Doherty power amplifier for the TD-SCDMA applications using a single dual-path integrated power transistor in over-molded plastic package reported to date.