Design and application of 100-2500MHz active mixer based on ADRF6655

Design and application of 100-2500MHz active mixer based on ADRF6655

The ADRF6655 from ADI is a high dynamic range active mixer with integrated PLL and VCO. It has an input frequency range of 100MHz - 2500MHz, an internal LO frequency range of 1050MHz to 2300MHz, an input P1dB of 12dBm, an input IP3 of 29dBm, a noise (SSB) of 12dB, a voltage conversion gain of 6dB, and an output matching impedance of 200 ohms. The ADRF6655 is mainly used in broadband communication equipment such as point-to-point microwave communication, wireless base stations, defense broadband and software defined radio (SDR), cellular repeaters, and communication test equipment. This article introduces the main features, functional block diagram, PLL and VCO block diagram of the ADRF6655, as well as 850MHz, 900MHz, 1200MHz, 1300MHz, 1600MHz and 2100MHz output matching networks, evaluation board circuit diagram and evaluation board configuration component table

. active mixer with integrated PLL and VCO. The synthesizer uses a programmable integer-N/fractional-N PLL to generate a local oscillator input to the mixer. The PLL reference input is nominally 20 MHz. The reference input can be divided by or multiplied by and then applied to the PLL phase detector. The PLL can support input reference frequencies from 10 MHz to 160 MHz. loop filter. The loop filter output is then applied to an integrated VCO. The VCO output at 2 × fLO is then applied to a local oscillator (LO) divider as well as to a programmable PLL divider. .

The mixer provides an input IP3 exceeds 25 dBm with 12 dB single sideband NF under typical conditions. The IIP3 can be boosted to ~29 dBm with roughly 20 mA of additional supplied current. The mixer provides a typical voltage conversion gain of 6 dB with a 200 Ω differential IF output impedance. The IF output can be externally matched to support upconversion over a limited frequency range.

The ADRF6655 is fabricated using an advanced silicon-germanium BiCM OS process. It is packaged in a 40-lead, exposed-paddle, Pb-free, 6 mm × 6 mm LFCSP. Performance is specified over a −40℃ to +85℃ temperature range.

ADRF6655 key features:

Broadband active mixer with integrated fractional-N PLL

RF input frequency range: 100 MHz to 2500 MHz

Internal LO frequency range: 1050 MHz to 2300 MHz

Flexible IF output interface

Input P1dB: 12 ​​dBm

Input IP3: 29 dBm

Noise figure (SSB): 12 dB

Voltage conversion gain: 6 dB

Matched 200 Ω output impedance

SPI serial interface for PLL programming

40-lead 6 mm × 6 mm LFCSP

Figure 1. ADRF6655 functional block diagram

Figure 2. ADRF6655 PLL and VCO block diagram

Figure 3. ADRF6655 mixer block diagram

Figure 4. ADRF6655 850MHz output matching network diagram (800MHz-925MHz output return loss is greater than 12dB)

Figure 5. ADRF6655 900MHz output matching network diagram (815MHz-1075MHz output return loss is greater than 12dB)

Figure 6. ADRF6655 1200MHz output matching network diagram (950MHz-1500MHz output return loss is greater than 12dB)

Figure 7. ADRF6655 1300MHz output matching network diagram (1075MHz-1525MHz output return loss is greater than 12dB)

Figure 8. ADRF6655 1600MHz output matching network diagram (140MHz-1680MHz output return loss is greater than 12dB)

Figure 9. ADRF6655 2100MHz output matching network diagram (2000MHz-2200MHz output return loss is greater than 12dB)


Figure 10. ADRF6655 evaluation board circuit diagram

ADRF6655 evaluation board configuration component table: