Low Power Mixer/AGC/RSSI 3V Receiver IF Subsystem

The AD607 is a 3 V low power receiver IF subsystem for operation at input frequencies as high as 500 MHz and IFs from 400 kHz to 12 MHz. It consists of a mixer, IF amplifiers, I and Q demodulators, a phase-locked quadrature oscillator, and a biasing system with external power-down.

The AD607’s low noise, high intercept mixer is a doubly balanced Gilbert cell type. It has a nominal –15 dBm input referred 1 dB compression point and a –8 dBm input referred third order intercept. The mixer section of the AD607 also includes a local oscillator (LO) preamplifier, which lowers the required LO drive to –16 dBm.

In MGC operation, the AD607 accepts an external gain-control voltage input from an external AGC detector or a DAC.

The I and Q demodulators provide in-phase and quadrature baseband outputs to interface with Analog Devices’ AD7013 (IS54, TETRA, MSAT) and AD7015 (GSM) baseband converters. A quadrature VCO phase-locked to the IF drives the I and Q demodulators. The I and Q demodulators can also demodulate AM; when the AD607’s quadrature VCO is phase-locked to the received signal, the in-phase demodulator becomes a synchronous product detector for AM. The VCO can also be phase-locked to an external beat-frequency oscillator (BFO), and the demodulator serves as a product detector for CW or SSB reception. Finally, the AD607 can be used to demodulate BPSK using an external Costas Loop for carrier recovery.

APPLICATIONS

* GSM, CDMA, TDMA, and TETRA Receivers

* Satellite Terminals

* Battery-Powered Communications Receivers

* Complete Receiver-on-a-Chip: Monoceiver® Mixer

−15 dBm 1 dB Compression Point

−8 dBm Input Third Order Intercept

500 MHz RF and LO Bandwidths

* Linear IF Amplifier

Linear-in-dB Gain Control

Manual Gain Control

* Interfaces to AD7013 and AD7015 Baseband Converters