New High End Spectrum and Signal Analyzer

The new R&S FSW signal and spectrum analyzer has been developed to meet demanding customer requirements. Designed to set standards in RF performance and usability, the analyzer has a wide analysis bandwidth and straightforward, intuitive operation that makes it particularly suitable for use in the aerospace and defense (A&D) sector and for developers of future communications systems.

The new, innovative internal architecture of the analyzer is claimed to deliver RF performance not previously possible in high end analyzers. For example, the first intermediate frequency (IF) of about 9 GHz allows image suppression up to 8 GHz without a YIG preselector. Traditionally, this frequency limit has been 3 to 4 GHz. The advantage is a very flat, stable, reproducible frequency response up to 8 GHz, which results in an absolute level accuracy of < 0.4 dB. This is especially significant for wireless applications in the 5 GHz bands, e.g. WLAN IEEE 802.11a/n/ac.

In addition, the R&S FSW uses different signal paths depending on the RF frequency. From 2 Hz to 30 or 40 MHz (depending on the resolution bandwidth used), the input signal is directly digitized by the 200 MHz, 16 bit A/D converter. Excellent sensitivity and a dynamic range down to the lowest frequency are the result.

The frequency range up to 1 GHz uses 1.31 GHz as the first IF. Due to the low first IF, a low frequency local oscillator and low frequency mixer with a very high dynamic range can be used. This results in a high third order intercept point of 30 dBm and very low phase noise. This makes the analyzer very powerful for this frequency band, which is of interest for many applications, such as professional and private mobile communications.

MICROWAVE FREQUENCIES

In the frequency range up to 8 GHz or the microwave range up to 26.5 GHz, where a YIG pre-selector is used, the R&S FSW offers a very high dynamic range up to microwave frequencies. At 20 GHz, with preamplifier, for example, the result is a displayed average noise level (DANL) of -166 dBm (1 Hz). With noise compensation, it nearly reaches the thermal noise floor with -173 dBm (1 Hz). The instrument not only delivers very good sensitivity, it also handles high signal levels. For example, an adjacent channel leakage ratio (ACLR) of -88 dB for a 3G signal at 2 GHz says a lot about its dynamic range. This is especially important for manufacturers of mobile radio
base stations.

The R&S FSW is believed to be the first analyzer to provide switched lowpass and bandpass filters in the RF frequency range for the measurement of harmonics. This is the most critical range, i.e. when measuring harmonics of mobile radio base stations or handsets. A second harmonic intercept of 70 dBm eliminates the need for external filters with switch matrixes. The R&S FSW reduces cost and the customer no longer has to calibrate the setup with external signal paths.

Developers of oscillators, synthesizers and transmit systems benefit from the analyzer's excellent dynamic range when performing phase noise measurements. Thanks to the in-house YIG technology and the custom R&S synthesizer ASICs, the R&S FSW achieves a phase noise of -137 dBc (1 Hz) at 10 kHz offset from the carrier (for a 1 GHz carrier). With this performance, the instrument detects signals close to the carrier that previously could not be seen with a spectrum analyzer. It also delivers a previously unattainable dynamic range for adjacent channel power measurements in narrow bandwidth applications such as public mobile radio.