A compact dual band 802.11n front-end module for MIMO applications using multi-layer organic technology

This paper presents a novel module technology for 802.11a/b/g/n applications. As an example, the authors demonstrate the first 6.0mm × 5.0mm × 1.2mm module which includes a dual band transmit section with pre and post power-amplifier (PA) filtering, and a dual band receive section with pre and post low-noise amplifier (LNA) filtering. The need for such modules has become imminent due to the arrival of multiple input multiple output (MIMO) based high data rate devices. The packaging technology used is multi-layer organic (MLO) technology comprising high performance liquid crystalline polymers (LCP) and Teflon-ceramic composites. The transmit (TX) section includes embedded filters in the organic package and a gallium arsenide (GaAs) power amplifier with control circuitry, harmonic filters, power detectors and single pole double throw switches. Similarly, the receive (RX) section includes embedded cellular rejection filters; silicon germanium (SiGe) based low noise amplifiers and switches. Key features of the module consist of less than 3% EVM at 19dBm and 17dBm output power for the 2.4GHz and 5GHz band respectively. The current consumption for these power levels is approximately 140mA with a quiescent current ≪80mA. The harmonic filters post PA restricts the harmonics to less than −50dBm/MHz harmonics at 19dBm output power. The 2.4GHz transmit filter before the power amplifier provides for greater than 25dB rejection of cellular frequencies below 2GHz and transceiver spurs above 3GHz. The 5GHz transmit filter provides for greater than 20dB rejection below 4GHz and above 6.8GHz to eliminate similar transceiver spurs. The RX sections provides greater than 12dB gain with 3.5dB noise figure in both bands, and superior rejection of cellular frequencies.