Antenna to Baseband Modules for 60 GHz FWA Networks
Peraso, a supplier of mmWave semiconductors and modules, has introduced the Perspectus line of 60 GHz modules for the fixed wireless access (FWA) market. These three high reliability modules can be used in point-to-point or point-to-multipoint networks and provide multi-Gbps throughput with low latency (see Figure 1). The Perspectus modules combine RFICs and baseband Si, developed by Peraso, with printed circuit board (PCB) antenna arrays (see Figure 2).
Providing a complete transceiver from antenna to baseband eliminates the design challenges of mmWave antenna design—a fine art—and matching components from different suppliers. With a USB 3.0 interface, they are straightforward to integrate with host processors. The modules are fully tested, do not require factory calibration and have FCC modular certification.
All Perspectus modules use Peraso’s PRS1165 transceiver IC, which integrates 16 high-power beamformer chains. The transceiver supports all six of the 802.11ad/ay channels from 57 to 71 GHz, and the frequency synthesizer and selectable RF filters support half-bandwidth channels and half-channel frequency steps. Longer link ranges can be achieved using channels 5 and 6, which are outside the oxygen absorption band. Peraso’s MAC PHY baseband processor, the PRS4601 B2E, provides the functionality for 802.11ad operation and supports point-to-point and point-to-multipoint capability. Peraso provides Linux drivers and offers various software/firmware versions optimized for FWA applications.
The three modules in the Perspectus line offer different antenna arrays, which provide various gain and fields of view (see Table 1). The arrays are integrated into the PCB to improve matching, reduce cost and increase reliability. One of the three modules, the PRM2141X, can connect to a high gain parabolic reflector, which enables Gbps data rates over links exceeding 20 km when using the upper channels.
Each module may be used as an access point (AP), station (STA) or in a peer-to-peer (P2P) configuration. Typically, the modules with wider fields of view (the PRM2141X or PRM2142X) will be used as APs, with the PRM2143X employed as the STA. For longer links, the PRM2141X with a dish can be used as the STA.
Peraso’s infrastructure software package enables point-to-multipoint networks with up to 32 STAs. Enhancements to the 802.11ad protocol such as directional beam scan and connect and STA focus can enhance beamforming performance over the extended distances supported by the hardware. The software also provides an aiming mode, to aid installation and link monitoring statistics, which are required to manage the network.
Perspectus modules are in production and have been adopted by wireless service providers as their primary solution for multi-Gbps service in urban and suburban networks. Evaluation kits and modules are available from Peraso and Richardson RFPD.