SWRA004A
High-Band Cascaded Receiver Section: LNA, Mixer, LO Buffer Amplifier
Cascaded High-Band Receiver Section: LNA, Mixer, and LO Amplifier
The TRF1500 high-band receiver section, shown in Figure 11, is an integrated front-end down converter designed to operate in the 1900 MHz frequency range. The high-band down converter consists of an LNA, an image-reject mixer, and LO buffer amplifier circuitry. Figure 11 details the cascaded block diagram with the image reject mixer detailed inside the dotted box.
The digital control allows the high-band receiver to operate in three different states to compensate for the environment in which the TRF1500 is operating. The high-band receiver can be operated in the normal state, where the LNA, mixer and buffer amplifier are on, the strong signal state, where the LNA is off and the mixer and buffer amplifier are on, or the transmit state, where the LNA bias current is increased to prevent compression when the transmitter is on.
The high-band receiver has a typical nominal gain of 26 dB, an IIP3 of -17.7 dBm and a noise figure of 4.66 dB when the receiver LO doubler is used and 4.35 dB when the high-band LO is directly driven.
Figure 11. Block Diagram of the High-Band Receiver Section
TRF1500 Integrated Dual-Band RF Receiver User’s Guide | 35 |
