آر اف (فرکانس رادیویی) و بی‌سیم سایر آی سی‌ و ماژول‌های آر اف

Product Attributes

Introduction

The AD9874 is a general-purpose IF subsystem capable of digitizing low-level IF input signals in the 10 MHz to 300 MHz range, with signal bandwidths from 6.8 kHz to 270 kHz. The AD9874 signal chain includes a low noise amplifier, mixer, bandpass Σ-Δ ADC, and decimation filter with programmable decimation factor. An AGC circuit provides the AD9874 with 12 dB of continuous gain adjustment. Auxiliary blocks include a clock synthesizer and LO synthesizer.

The AD9874's high dynamic range and inherent anti-aliasing characteristics provided by the bandpass Σ-Δ converter enable it to handle blocking signals 95 dB stronger than the desired signal. This feature can typically reduce radio costs by relaxing IF filtering requirements. It also supports multimode radios with different channel bandwidths, allowing the IF filter to be specified based on the maximum channel bandwidth.

The SPI port allows many AD9874 parameters to be programmed, enabling the device to be optimized for any given application. Programmable parameters include synthesizer division ratios, AGC attenuation and attack/decay times, received signal strength level, decimation factor, output data format, 16 dB attenuator, and selected bias currents. For battery-powered applications, LNA and mixer bias currents can be further reduced at the expense of performance.

Applications

• Multi-mode narrowband radio products
• Analog/digital UHF/VHF FDMA receivers
• TETRA, APCO25, GSM/EDGE
• Portable and mobile radio products
• Base station applications
• Satellite communication terminals