The PE128300 from pSemi is a Dual-channel TD Up-Down Converter with an RF frequency from 24.25-29.5 GHz to support 5G FR2 n258 and n257 frequency bands. Up to 16 different mode definitions are pre-stored and selectable via a single-byte SPI command. Mode definitions contain seven elements: LO power on/off, V/H RX power on/off, V/H TX power on/off, and V/H T/R switch state. Typical modes used are TX, RX, idle, sleep, and loopback.
In transmit mode, the input to a channel is applied to IF_I and IF_Q 50 ohm impedance ports. The signal passes through circuits which adjust the relative amplitude and phase of the I/Q signals. T/R switches route the IF signal to the transmit image reject mixer. Next, the up-converted signal is either directly connected to an RF amplifier or, in the packaged case, is routed through a bandpass filter inside the package and amplified afterward. The RF amplifier outputs route through T/R switches to IC bump contacts.
In receive mode, the input arrives at the RF 50Ω port and is then routed to the RX image reject mixer by a T/R switch. After the down-conversion, the signal passes through the I/Q quadrature correction circuits. The I/Q correction digital control is multiplexed between TX and RX stored coefficients depending upon the active mode.
