Compared with 4G network, the speed of 5G network can reach several times or even tens of times of 4G, in which millimeter wave technology is undoubtedly a key link in the 5G era, and has an important application prospect.
As a chip industry, the relevant IC chip testing in the 5G era is a great challenge to test engineers. IC testing needs a fast, accurate and cost-effective testing solution to ensure the reliability of the new chip design.
Five challenges in 5G broadband testing.
1. The waveforms become wider and more complex.
The 5G new slot contains two different waveforms:
Downlink cyclic prefix OFDM (CP-OFDM) and uplink CP-OFDM.
Uplink discrete fourier transform spread spectrum orthogonal frequency division multiplexing (DFT-S-OFDM), which is similar to the single carrier frequency division multiple access system (SC-FDMA) of LTE.
Researchers and engineers face new challenges in creating, distributing, and generating 5G waveforms when testing 5G devices. Engineers need to process highly complex and standard uplink and downlink signals with much larger bandwidth than previous signals. They need to allocate a variety of resources; modulate and encode signals; demodulation and detection of information and phase tracking; single carrier and continuous and discontiguous carrier aggregation configurations.
Solution: select tools that conform to the 5G standard, generate and analyze the required waveforms, and share these waveforms between different test stations to fully analyze the characteristics of the DUT.
2. The instrument must be broadband and linear and must be able to cover a wide range of frequencies cost-effectively.
RF engineers have been working on millimeter wave test systems for aerospace and military industries, but these systems are so expensive that there are no suitable millimeter wave test systems for the mass market semiconductor industry. Engineers need cost-effective test equipment to configure more test sets to shorten the time to market. These new test stations must be able to support high linearity; provide high amplitude and phase accuracy over high bandwidth; have low phase noise; support a wide range of frequencies to support multi-band devices; And be able to test whether the device can coexist with other wireless standards. In addition to powerful hardware, software-based modular testing and measuring stations must also be able to quickly adapt to new testing requirements.
Solution: invest in broadband test platforms that can evaluate the performance of existing and new frequency bands. Choose instruments that can not only coexist with current standards, but also adapt to future changes.
3. Component feature analysis and validation require more testing.
Processing wide signals below 6 GHz and millimeter wave frequency signals requires the analysis and verification of the performance of RF communication components. Engineers will not only test innovative multi-band power amplifiers, low noise amplifiers, duplexers, mixers and filter designs, but also ensure that the new improved RF signal chain supports the simultaneous operation of 4G and 5G technologies. In addition, in order to avoid a large amount of loss during propagation, millimeter wave 5G test system also needs beamforming subsystem and antenna array, which requires a fast and reliable multi-port test solution.
Solution: ensure that your test system can handle multi-band and multi-channel 5G devices to meet the needs of beamformer, FEM, and transceivers.
4. The wireless test of large-scale MIMO and beamforming system makes the traditional measurement highly dependent on space.
When testing 5G beamforming equipment, engineers face the challenge of analyzing transmitting and receiving paths and optimizing the reciprocity of receiving and transmitting antennas. For example, when the transmit power amplifier enters the compression region, it will produce amplitude and phase distortion and other thermal effects, but the LNA of the receiving path will not produce these phenomena. In addition, the tolerances of phase shifters, variable attenuators, gain control amplifiers, and other devices may result in different phase shifts between channels, thus affecting the expected directivity diagram. The measurement of these effects requires the use of empty (OTA) testing technology, which makes the traditional measurements such as TxP, EVM, ACLR and sensitivity highly dependent on space.
Solution: OTA testing technology enables RF measurements while quickly and accurately controlling motion, allowing you to accurately analyze the characteristics of the 5G beamforming system in the expected time.
5. Mass production testing requires that the test system can be extended quickly and efficiently.
The growing demand for new 5G applications and vertical industries has led to an exponential increase in the number of 5G components and devices that manufacturers need to produce each year. The challenge for manufacturers is to provide quick ways to calibrate multiple RF paths and antenna configurations for new equipment and to improve the testing speed of OTA solutions to ensure the reliability and repeatability of manufacturing test results. However, for the mass production of RFIC, the traditional RF darkroom will occupy most of the production plant space, so that the plant can not place the equipment needed for other processes, resulting in the interruption of the material processing process, which will greatly increase capital expenditure. To address these problems, OTA-enabled IC sockets (small RF housings with integrated antennas) have been introduced, which significantly reduce the space required for semiconductor OTA testing.
Solution: select a ATE platform that extends the experimental 5G instrument to the production site to simplify the data association between characteristic analysis and production testing.