New-Tech Europe Magazine | May 2018

Affordable Solutions for Testing 28 GHz 5G Devices with Your 6 GHz Lab Instrumentation

Jose Garcia and Miroslav Karas, Mini-Circuits outfitted with test

The capabilities that define the 5G wireless standard will require utilization of wider bandwidths across more regions of spectrum thananycurrentwireless technology. 5G communications will eventually occupy multiple bands from below 6 GHz to above 60 GHz. For now, much of the development effort is divided among sub-6 GHz bands for vehicular connectivity and longer- range transmissions, and the 26, 28, 38 and 60 GHz bands for enhanced mobile broadband applications. The migration to higher frequencies and the multi-band nature of the technology pose a variety of unique challenges for designers developing 5G devices and network equipment. Significant among these is the high cost of instrumentation for test and measurement over such a wide range of frequencies. Many RF test labs are already

and measurement equipment capable of measurements up to 6 GHz. For companies venturing from applications below 6 GHz up to the 28 GHz or even 38 GHz bands, the cost of acquiring additional dedicated instrumentation supporting measurements up to 40 GHz can be prohibitive, increasing from tens of thousands to the order of hundreds of thousands of dollars. Fortunately, with some creativity and a few readily available components, customers can adapt the equipment they already have in the lab to perform testing on devices operating in higher frequency bands without the need for heavy investment in new equipment. This article describes a variety of relatively affordable setups using off-the-shelf Mini-Circuits components, which allow users to

test devices operating in the 28 GHz band with a 6 GHz spectrum analyzer or network analyzer and a signal generator operating up to 6 GHz. Functional block diagrams are presented and explained along with recommended components and possible extensions. Test Setup Overview – Up/Down Conversion with a Wideband Mixer Let’s assume for our case that we want to assemble a test setup for uplink and downlink testing of 28 GHz DUTs using a spectrum analyzer and a signal source (synthesizer or signal generator), both with operating frequencies up to 6 GHz. For downlink testing, a wideband mixer with an LO frequency of 24 GHz can be used to convert a 4 GHz test signal from the signal

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