Spectrum Analyzers Brian Yee W 6 BY Microwave

Spectrum Analyzers Brian Yee, W 6 BY Microwave Update 2010 Cerritos, CA

Presentation Outline n n n Basic design and evolution Applications Overview of available models Issues for prospective buyers And…

Basic Concepts – Key Components MIXER RF IN IF Detector Display SWEEP OSCILLATOR A simple swept receiver with a visual display • A brief history of some spectrum analyzer developments can be found at: http: //www. hpmemory. org/wb_pages/wall_b_page_04. htm

Some Refinements… MIXER RF IN FILTER SWEEP OSCILLATOR Detector FILTER Display Problems with this approach: • Limited frequency range • Can’t look at low frequencies • Spurious signals show up • Narrow sweeps difficult

More Refinements RF IN MIXER FILTER Resolution Video bandwidth FILTER Detector FILTER SWEEP OSCILLATOR/ Better spur rejection SYNTHESIZER Better frequency accuracy Display

High-end approach 9 KHz – 2 GHz 3. 6 GHz MIXER 3. 3 GHz OSC Resolution Bandwidth 321. 4 MHz MIXER RF IN LP FILTER MIXER 21. 4 MHz FILTER 300 MHz OSC 2 – 22 GHz MIXER FILTER 321. 4 MHz FILTER SWEEP OSCILLATOR/ SYNTH 2 - 6 GHz Detector FILTER Video Bandwidth Display

Applications • Checking the power of amplifiers (with the proper pad) • Checking for harmonics • Phase noise measurement • Modulation measurement • Channel power measurement

Tektronix 7 Lxx, 1 Lx Plug-ins In the beginning…

Tek 7 Lxx Series

Tektronix 49 x Series – 22 GHz 492 popular, lots available, mm-wave mixers available, digital/analog display 494 AP top of the line Some limited-frequency range units (496, 492 P’s)

Tektronix 27 xx Series – 1. 8 GHz Primarily made for field use, service shops and CATV servicing

Tektronix 275 x Series – 22+ GHz Rack mount variation of 494 AP, some models mm-wave capable

Tektronix 279 x – 26 GHz Nice…

Tektronix 2782/4 – 40 GHz Even nicer… • CRT has color LCD shutter • 2782 has 33 GHz range, 2784 has 40 GHz range • MM-wave operation possible with internal duplexer • Expensive

HP 851 A Display unit shown, RF unit goes on the bottom. Very basic functionality, but more than 1 L 20

HP 141 T – 18 GHz Nice unit, lots available 3 types of plug -ins up to 18 GHz Uses storage tube

HP 8557 Several plug-ins available

HP 8565 A – 22+ GHz Many available Storage display with digital readouts Can use external mixers

HP 8569 A/B – 22+ GHz • Very popular, lots available • Can use external mixers • Digital storage display, GPIB

HP 8568 A/B, 8566 A/B, 8567 A – 22 GHZ+ • An industry standard • One of the best displays • Lots available • Serviceable • Can use external mixers, auto signal ID

HP 859 x Series • Low-end portable • Subject to drift • Intended for field service market • Lots available

HP 856 x Series Many of the features of the 8566 series and more crammed into a portable unit • Synthesized • Available in several frequency ranges • Some can use external mixers • Expensive

IFR • 1 GHz unit • Lots available

Advantest 326 x, R 346 x series Nice units, lots of features, hard to get service info

Advantest U 36 xx Series Microwave units to 26+ GHz

Anritsu MS 710 A/B/C/D D model can accept either Tek or HP mixers

Anritsu MSxx Series

Others What to look for: Marconi - Service manual available Instek - Physical condition AIL/Eaton - “unobtainium” parts Systron Donner Rohde and Schwarz – expensive Wandel & Goltermann Various Chinese makes - Serviceability

Recent advances • Smaller units with more capability • DSP, more complex measurements • Demodulation of various communications formats • Better displays • Faster speed • Interface with other instruments such as power sensors

The MUD 2010 Grand Prize!!! • 100 KHz to 3 GHz freq. Range • 6. 5” color TFT • 4 -hour battery life • One-button power measurement • Spectrogram • USB power sensor support • Field strength measurement • Much more…