A direct-conversion RF transmitter for 4G LTE applications

In this paper, a 2.6 GHz direct-conversion radio frequency (RF) transmitter module is implemented using application-specific integrated circuits based on a link budget for fourth generation (4G) long term evolution (LTE) applications. It consists of a modulator, a bandpass filter (BPF), and a power amplifier (PA). The power consumption of the RF transmitter is 1.8 W. The measurements of the RF transmitter are made, revealing that a gain is 52.15 dB, a single sideband (SSB) output power is 25.15 dBm, a local oscillator (LO) leakage is -32.1 dBc, a sideband suppression is 54.47 dB, and the error vector magnitude (EVM) of a quadrature phase shift keying (QPSK) signal is 2.66%.