MiniSA - The Miniature Spectrum Analyzer
Many of my recent consulting jobs have been related to wireless communications. I've found some gaps between commonly available tools and what a designer needs for this type of work.
Click here to order the MiniSA.
To facilitate easier development of wireless systems, I have created a very low cost 2.4 GHz Spectrum Analyzer. This design was featured in the April 2006 issue of Circuit Cellar magazine. Now it has been updated with enhanced software and the price is even lower !
This device will let you observe radio signals in the 2.4 GHz band. This band is heavily used throughout the world for many types of low power, short distance communications. Examples of this are WiFi (802.11b), Bluetooth, ZigBee, Wireless USB, security systems, wireless video cameras and cordless phones. In addition, police radar and microwave ovens use this frequency band. This spectrum analyzer will not allow you to "listen in" to any of these communications, but it will let you see the transmissions, understand what frequencies they are at, understand how strong the signals are and see how those signals relate to other signals. It can help you resolve networking problems related to interference from other devices. It can also be useful for those designing 2.4 GHz radio systems - just place the resizable spectrum analyzer window anywhere on your PC screen and observe at a glance your transmissions as well as transmissions from the other end of your wireless link. Although your spectrum analyzer is not a calibrated piece of test equipment (such units cost much, much more!), it can be extremely useful for many tasks that were previously done with much bigger and more expensive equipment.
The Mini Spectrum Analyzer comes in two parts. The RF (radio frequency) portion is a small circuit board with a special radio communications chip on it. This board plugs into another board, called Arduino. Arduino is a very popular microcontroller development board that has a microprocessor chip that controls the radio and a USB port for communication with a PC.
Also included is Windows software for display of the spectrum.
Features:
- Small size
- Low cost
- Sensitive receiver (-90 dBm)
- Covers 2.4 GHz ISM band (2.40 - 2.48 GHz)
- 333 Khz resolution allows entire 2.4 GHz ISM band to be captured in one sweep
- Easy-to-use software displays the frequency spectrum on a PC
- Spectrum can be zoomed and scrolled to focus on desired frequencies
- Supports use of template overlays for frequency channel identification and min/max bounds checking
- Spectrum data can be exported to Excel for analysis
- Ideal for debugging wireless communications software
- System requirements: PC running Windows 2000/XP/Vista with spare USB port.
MiniSA In Use
The following video shows some uses of the MiniSA.
If the embedded video image does not appear, click here to open in a separate page.
FAQ
Q: Can you bundle the spectrum analyzer with an Arduino and sell it to me as a package?
A: Sorry, not at this time. Possibly in the future.
Q: You say that the circuit requires an Arduino Diecimila. Can I use some other kind of Arduino board?
A: No.
Q: Can the spectrum analyzer be modified to tune frequencies outside the 2.4 GHz band?
A: Sorry, the radio chip used in the design only tunes 2.4 GHz.
Q: Are the schematics or PCB layout of software source code available for download?
A: Not at this time. It is possible that it may be available in the future.
Q: You used to sell a spectrum analyzer in a plastic enclosure with an external antenna. Is that unit still available for purchase?
A: Not as a standard product, but special builds of that unit can be made for orders of 20 units or more.
Q: You say you ship only to North America. Can you ship to other areas?
A: Sorry, at this time shipments are only made to North America.
Q: You say that you only ship via USPS. Can you ship using another carrier?
A: Sorry, only USPS Priority Mail.
Q: You say that you only accept PayPal payments. Can I send payment via check or credit card?
A: Only PayPal is accepted. PayPal accepts checks and credit cards.
Ordering
Click here to order the MiniSA.Note that you will also need to order an Arduino Diecimila board and USB cable. This board can be purchased from any of the vendors listed on this page.
