Microwave Journal
www.microwavejournal.com/articles/35413-signal-and-spectrum-analyzer-with-83-ghz-analysis-bandwidth

Signal and Spectrum Analyzer With 8.3 GHz Analysis Bandwidth

February 12, 2021

Regarded as a leading instrument for ultra-wideband signal analysis, the R&S FSW signal and spectrum analyzer offers an input frequency range to 90 GHz and a recently introduced option extending the analysis bandwidth to 8.3 GHz.

While already standard in radar and communications, bandwidths of 4 GHz or more are becoming common in multiple industries with the trend to higher frequency applications. Traditionally, the approach for signal analysis in these wideband systems has resorted to workaround practices, since a user-friendly, single box solution was not available. Since the high speed analog-to-digital converters needed to sample the modulated signal were only available in oscilloscopes, work-around solutions used a signal and spectrum analyzer as a wideband down-converter feeding the signals to an oscilloscope.

While this approach produces good results, Rohde & Schwarz offers a more convenient alternative: a single box solution offering ease of automation and full datasheet capabilities for both signal and spectrum analysis. The R&S FSW signal and spectrum analyzer now includes options to extend the internal signal analysis bandwidth to 4.4, 6.4 and 8.3 GHz. The R&S FSW enables users to take advantage of the analyzer’s wide dynamic range and high sensitivity in a single instrument. With its precision measurement and low error vector magnitude performance supporting large modulation bandwidth, the R&S FSW provides a future-proof solution for the measurement challenges of many applications.

SAFETY ON THE ROAD

Figure 1

Figure 1 Analysis of automotive radar FMCW signal at 77 GHz.

In radar systems, wider bandwidth improves range resolution. Applied to automotive radar, frequency modulated continuous wave radars are considered the state-of-the-art architecture, as they provide extremely good resolution at short range. Current automotive radar systems operate in E-Band (76 to 77 or 77 to 81 GHz) with bandwidth as high as 4 GHz (see Figure 1). This performance imposes stringent requirements on the signal processing chain, particularly the analog components, which must have better signal-to-noise ratio and frequency stability. The R&S FSW signal and spectrum analyzer offers the frequency coverage and bandwidth to assess the performance of these high performance systems.

With higher signal bandwidth and the growing number of radar sensors on vehicles, the risk of interference among sensors is increasing. Signals from neighboring vehicles can limit radar sensor functionality and, worst case, cause driver assistance systems to make incorrect decisions. To avoid this, precision measurements are necessary to identify potential faults. Validating compliance with ETSI and FCC standards requires both signal and spectrum analysis to measure the occupied bandwidth and detect spurious emissions. The R&S FSW signal and spectrum analyzer offers both signal and spectrum analysis.

COMMUNICATIONS

Figure 2

Figure 2 IEEE 802.11ay channel bonded signal spanning 8 GHz.

In communications, increasing frequency and modulation bandwidth has a long history, as each new generation of technology provides higher content. 5G introduced the use of wideband channels at mmWave frequencies in handsets. Digital predistortion (DPD) is widely used to correct the nonlinearities of power amplifiers. To analyze the performance of DPD systems, both the user channel and adjacent channels must be measured. For an 800 MHz multicarrier 5G NR signal, this requires up to 4 GHz analysis bandwidth. The 802.11ay standard for Wi-Fi supports channel bonding, which leads to signals with bandwidths greater than 8 GHz at 60 GHz (see Figure 2). To support the data rates enabled by 5G, Gbps point-to-point radio links are used at E- and D-Band, and R&D is beginning on communications links in the sub-THz bands.

Future high throughput satellites, being designed to support Tbps capacity, will also move to higher frequencies and wider bandwidths, with bandwidths expected to reach 6 to 8 GHz at frequencies to 90 GHz.

DEFENSE

A radar system designed for military applications will typically change its modulation and frequency with each pulse and hop across a wide frequency range. These pulse-to-pulse changes reduce the probability of intercept by enemy reconnaissance and subsequent jamming. Jammers attempt to reduce the sensitivity of the radar or render it completely blind by using wideband noise or frequency agile signals. The R&S FSW’s wideband acquisition capability can analyze wideband frequency hops, for testing both radar and jamming systems.

With the expanded analysis bandwidth options and dedicated measurement applications tailored to meet industry needs, the R&S FSW is ready for whatever direction technology takes. As a testament to the instrument, Rohde & Schwarz is relying on the wide analysis bandwidth capabilities of the R&S FSW for its own R&D on new wireless systems.

Rohde & Schwarz
Munich, Germany
www.rohde-schwarz.com