Microwave Journal

Affordable, 43.5 GHz Real-Time Spectrum Analyzer Doubles As Vector Signal Analyzer

September 13, 2021

Signal Hound is launching its latest innovation in accurate and powerful spectrum analysis: the flagship SM435B 43.5 GHz spectrum analyzer expands frequency coverage to mmWave at an affordable and very competitive price point. It is available for pre-order and will be released mid-October 2021.

The SM435B is a high performance spectrum analyzer and monitoring receiver. Tuning from 100 kHz to 43.5 GHz, the analyzer has up to 160 MHz of instantaneous bandwidth (IBW), 110 dB dynamic range, ultra-low phase noise and 1 THz/sec sweep speed at 30 kHz resolution bandwidth (RBW) using Nuttall windowing. Currently the most affordable mmWave analyzer on the market, the SM435B offers performance rivaling the most expensive spectrum analyzers.

The instrument’s RBW range is from 0.1 Hz (≤ 200 kHz span) to 3 MHz (any span) with 40 MHz IBW or 30 kHz to 10 MHz with 160 MHz IBW. The SM435B offers 5 kHz to 40 MHz of selectable I/Q streaming bandwidth and can capture a 2 s I/Q block at 160 MHz IBW for external analysis on a PC. The I/Q streaming can be locked to GPS for precision time stamping.

Figure 1

Figure 1 Real-time spectrum measurement using Spike with the SM435B.

Figure 2

Figure 2 With Spike, the SM435B performs digital modulation analysis with EVM measurements, doubling as a vector signal analyzer.

Figure 3

Figure 3 With Spike, the SM435B offers a noise figure analysis mode, providing noise figure and gain measurements and data export.

The accuracy of the SM435B’s oven-controlled crystal oscillator is ±5 × 10-10 when locked to the GPS signal. Aging is specified at no greater than ±5 × 10-9 per day and thermal drift is within ±1 × 10-8 over -40°C to 65°C.

To ensure low VSWR over the mmWave frequency range, the instrument uses 2.4 mm connectors. Typical input VSWR is specified at 1.6:1.

Signal processing is distributed between a powerful Altera FPGA and an external PC with Intel Core i7 processor. Using its local API, the SM435B can interface to an automated monitoring system or automated test equipment, providing the capability for users to insert their own DSP algorithms into a calibrated stream of I/Q data.

Spike Software Adds Capabilities

Spike, Signal Hound’s proprietary and complementary spectrum analyzer software, is included with the SM435B. Compatible with the entire line of Signal Hound spectrum analyzers and tracking generators, the software provides full device control, a configurable spectrogram display, user interface and a variety of analysis modes, adding powerful RF analysis capabilities. Spike adds several capabilities that enhance the spectrum analyzer’s measurements:

Real-Time Spectrum Analysis — In today’s wireless environment, serious measurements require real-time capabilities. With many signals—complex modulated communications, interference, pulsed tactical signals—the signal energy is sporadic, non-recurring or even random. With traditional spectrum analysis, these signals are nearly impossible to catch in an analyzer window or trigger on. Spike enables real-time measurements (see Figure 1).

Digital Modulation Analysis— In addition to the spectrum display, Spike’s digital modulation analysis capabilities turn the spectrum analyzer into a vector signal analyzer with the capability to perform EVM measurements and view the constellations of several PSK and QAM modulations (see Figure 2).

Noise Analysis — The noise figure mode measures noise figure and gain (see Figure 3). The noise figure is computed using the Y factor technique from several measurements taken by the SM435B. The data can be exported in a CSV format for analysis.

Phase Noise — Spike’s phase noise measurement application enables single sideband phase noise to be measured. The simple, industry standard phase noise measurement is straightforward and makes the SM435B a cost-effective phase noise test system.


Signal Hound has a tradition of providing value and performance in RF signal analysis and generation. That tradition continues with this latest model in the SM line of spectrum analyzers. Offering features to help measurement workflow on the lab bench, the production line or in the field, the SM435B extends advanced spectrum analysis to 43.5 GHz. The analyzer provides a good entry point for affordable access to mmWave spectrum analysis, whether using Signal Hound’s application programming interface, third-party or in-house custom software. This high performance, affordable spectrum analyzer supports test and analysis needs, able to monitor new waveform standards, including 5G.

As Signal Hound prepares the SM435B for production and delivery, the company wants valued customers and Signal Hound enthusiasts to have the opportunity to pre-order and plan for procurement in early Q4 of this year. Signal Hound’s customer service team can assist with pre-production purchase orders.

Signal Hound
Battle Ground, Wash.
SM435B info: