5G Radiohead
5G combines the existing spectrum with the new millimeter wave (mmWave) spectrum, and it’s this higher-frequency mmWave that provides both benefits and design challenges for 5G. At these frequencies, patch antenna size is greatly reduced for radioheads, but conversely, signal attenuation is high, so antenna systems use beamforming arrays to concentrate and direct the signal energy to overcome these propagation losses.
An antenna array the size of your palm may cover one side of a radiohead module with beam steering RFICs, transceivers, and power amplifiers (PAs) driving them from the reverse side of the PCB. Such compact high-frequency modules demand technology-aware design platforms that support discrete and embedded RF component design and system integration with in-design electromagnetic (EM) and thermal analysis, RF circuit simulation, and workflow support for co-design of IC, package, and modules with GaAs, GaN, and Si technologies.
To meet this fundamental 5G design need, Cadence offers Intelligent System Design, which leverages the Virtuoso RF Solution and the AWR Design Environment platform for RF MMIC and PCB IP development along with in-design multiphysics analysis software so engineers can account for all these concerns within an integrated design platform across the entire chip, package, and PCB system.
RFICs for 5G will necessarily contain many digital functions, such as decimation, clipping, and particularly digital pre-distortion; essential for power amplifier linearity and the uncompressed constellation diagrams demanded by the high-performance 5G modulation scheme 1024-QAM. To enable this type of digitized RFIC design, Cadence provides Virtuoso Digital Implementation, which works with the Virtuoso RF Solution through a common OpenAccess database, Spectre® AMS Designer and Spectre eXtensive Partitioning Simulator (XPS), all elements of the Cadence Mixed-Signal Solutions.
System-level design and detailed evaluation of digital pre-distortion algorithms is achieved with Cadence AWR Visual System Simulator (VSS) co-simulating with RF PA IP from AWR Microwave Office software and/or the Cadence Spectre RF Option.
Narrowly formed beams create a need for many more radioheads, with line-of-sight inside and outside of buildings and on masts, and here small form-factor and low cost is key, as well as temperature ranges from -40℃ to 125℃. Using the Allegro® PCB Designer RF Option for PCB design, with Cadence connections to mechanical CAD partners Dassault Systemes, PTC, and Siemens, means the radiohead PCB and housing can be co-designed for optimal performance, size, and cost.
With so many antennas to drive for massive multiple input/multiple output (MIMO), power reduction is key. With a wide variety of digital baseband, RF, and hybrid beamforming architectures to help meet this goal, the Cadence Low-Power Solution can help meet the low-power objectives for radiohead design.