Analog Devices ADMV4540 Product Info

The ADMV4540 is a highly integrated quadrature demodulator with integrated synthesizer ideally suited for next generation K band satellite communication.

The RF front end of the ADMV4540 consists of two low noise amplifier (LNA) paths, each with an optimal cascaded, 5 dB, double sideband noise figure at maximum gain, while minimizing external components. The dual paths allow support for antenna polarization. Selection of the LNA path can be done through the SPI.

The LNA output is then downconverted to baseband using an inphase and quadrature (I/Q) mixer. The I/Q mixer output is then fed into fully differential low noise and low distortion programmable filters and variable gain amplifiers (VGAs). Each channel is capable of rejecting large, out of band interferers while reliably boosting the wanted signal, thus reducing the bandwidth and resolution requirements on the analog-to-digital converters (ADCs) of the system. The excellent matching between channels and their high spurious-free dynamic range (SFDR) over all gain and bandwidth settings make the ADMV4540 ideal for satellite communication systems with dense constellations, multiple carriers, and nearby interferers.

The three filter corners of 125 MHz, 250 MHz, and 500 MHz are all programmable via a serial peripheral interface (SPI). The filters provide a sixth-order Butterworth response with −3 dB corner frequencies of 141 MHz, 282 MHz, and 565 MHz. For operation beyond 565 MHz, the filter can be disabled and completely bypassed, thereby extending the −3 dB bandwidth up to 900 MHz.

The high dynamic range baseband output amplifiers of the ADMV4540 provide an overall nominal conversion gain of 57 dB. The three baseband voltage variable attenuator (VVA) pins (VCTRL_BBVVAx) of the ADMV4540 can be used for automatic gain control (AGC), giving the ADMV4540 a wide RF input dynamic range.

This feature rich device contains an integrated fr