Portable, handheld spectrum analyzers such as the new model 9102 from Boonton Electronics allow engineers to bring their measurement gear to a site, rather than the other way around. This battery-powered test tool is a mere 355 X 190 X 91 mm but packs all the measurement power of a rack-mount spectrum analyzer. It covers a frequency range from 100 kHz to 4 GHz and features a built-in frequency counter for accurately identifying received signals with 1-Hz frequency resolution.
The handheld model 9102 spectrum analyzer (see figure) tunes across a selected span from 10 kHz to 4 GHz (full scan) with 1-kHz tuning resolution. It can also perform zero-span (0 Hz) measurements for evaluating modulated signals. The instrument includes a wide range of resolution-bandwidth filters, from 100 Hz to 1 MHz; these can be set manually or automatically selected by the 9102 based on other measurement parameters. Similarly, video-bandwidth filters can be selected manually or automatically from 10 Hz to 1 MHz. Frequency sweep times can be set from 1 ms to 250 s. The aforementioned frequency counter works on signal levels as low as -90 dBm. The counter can be set for different frequency resolution levels of 1 Hz, 10 Hz, and 100 Hz.
The 9102 exhibits a displayed average noise level (DANL) of typically -130 dBm from 10 MHz to 1 GHz and typically -135 dBm from 1 to 4 GHz. The reference level can be set from -100 to +30 dBm with 0.1-dB resolution. The analyzer's dynamic measurement range is defined by the maximum measurable input level, which is +20 dBm, and the DANL. (The 9102 actually handles input levels to +30 dBm without damage.) The dynamic display range (how much can be shown on the screen at one time) is 70 dB. To assist in measuring high-level signals, the 9102 is equipped with as much as 50-dB input attenuation, which can be added in 10-dB steps. With the attenuator set to 10 dB, the spectrum analyzer shows a quite respectable level accuracy of ±1 dB from 10 MHz to 3.6 GHz.
The portable analyzer shows test results on a 6.5-in. color VGA thin-film-transistor (TFT) display screen with 640 X 480-pixel resolution. The microprocessor-powered instrument is assisted by a field-programmable gate array (FPGA), which handles digital-signal-processing (DSP) chores on captured signals. It performs a number of more complicated measurements with the push of a button, including channel power, adjacent-channel power ratio (ACPR), and occupied-bandwidth (OBW) measurements. The analyzer is armed with a full complement of detectors, including positive/negative, peak, positive peak, negative peak, and sample detectors, for performing electromagnetic-interference (EMI) measurements. An optional root-mean-square (RMS) detector supports measurements on digitally modulated signals. The 9102 allows operators to set as many as six measurement markers, as many as 99 limit templates, and pass/fail limit lines.
Another option equips the 9201 with a 1-MHz-to-4-GHz tracking generator for reflection and distance-to-fault measurements. The tracking generator can be adjusted from -30 to -10 dBm for performing measurements on both active and passive components.
The 9201 weighs just 7 lbs. (3.2 kg) with its rechargeable battery and the optional tracking generator. It includes a headphone jack, an RJ-45 local-area-network (LAN) connector, and a serial interface.