Realizing 5G and IoT RF systems with off-the-shelf components: Page 3 of 5

June 29, 2017 //By How-Siang Yap, Keysight Technologies, Inc.
Architecting and building RF systems for 5th Generation (5G) and Internet-of-Things (IoT) applications to achieve the best performance at the lowest cost and in the shortest time places intense pressure on the engineers who are tasked to do the work. This article explains how the process can be performed efficiently through accurate RF system simulation with real off-the-shelf components and fast multi-stage impedance matching synthesis on a printed circuit board layout.

5G system realization with off-the-shelf parts

Off-the-shelf parts from vendors such as Mini-circuits, Analog Devices, Qorvo, Marki, and Avago implemented into modular tiles by X-Microwave were used in the realization of the 28 GHz 5G RF receiver system as shown in Figure 3. Each modular tile, called an X-Block, includes all the biasing and peripheral passive components for the active device such as LOs, mixers and amplifiers. They are characterized by measured X-parameters or Sys-parameters at their co-planar interconnect reference planes for simulation to accurately model how they are being used in the actual system hardware. They are connected together by a flipped, co-planar laminate that spans the small gap between the X-blocks and is held down by compression, without soldering, to work reliably up to 67 GHz. The 1.9 mm test launchers are also held down by compression so that the X-blocks can be reused with no damage. When the prototype is finalized, the same composite layout can be used directly for production, since they are all built on the same laminate material.


Figure 3:  Hardware prototype of 28 GHz receiver system using X-Blocks from X-microwave. What-You-Simulate-Is-What-You-Get without discrepancies caused by interconnect parasitics or inaccurate system models.

When the system was measured, the agreement with the simulated result was unexpectedly close, as shown in Figure 4 and is within the uncertainty error of the vector signal analyzer.


Figure 4:  Measured versus Simulated Error Vector Magnitude with different input RF power. Excellent correlation to within measurement uncertainty of test
instruments.

Design category: