What is it?
There is equipment at Harvey Mudd which has the ability to conduct high frequency measurements of circuits and antennas. Specifically, we have an anechoic chamber, a calibration antenna, two VNAs, two spectrum analyzers and many signal generators. Some of these instruments are useful for measurements of up to 28 GHz!
Prof. Spencer's research group uses this equipment heavily and so do many clinics. You too could use it!
Note that this lab is a recharge facility, meaning that you are responsible for buying consumable items that you use. That usually means buying SMA cables for your own projects. It also means replacing any damaged items from the lab's lending library of RF modules.
Getting Access to the Lab
Read the ground rules of the lab (on this page) and the RF basics document (in the "Other Documentation" section below), fill out the RF Lab access form, and then schedule a meeting with Prof. Spencer. He'll show you the lab and then administer a quick oral examination on basic safety and equipment maintenance. If you pass then he'll discuss a test plan and the proper techniques for accessing the room.
The access exam consists of the following, all without referring to notes but with fairly generous help from the administrator:
- List all of the ground rules of the lab
- List the three main ways that RF equipment can get damaged (AC power, DC offset, Mechanical) and discuss some examples
- Calculate the power driven into a 50 Ohm load by a 1Vzp sinusoid with 0VDC offset.
- Point out how to tell the difference between damaged and undamaged SMA cables.
- Demonstrate proper handling, connection and disconnection of an SMA cable.
Ground Rules You Should Know
- Stay safe! You're more dangerous to most things in the RF lab than they are to you, but don't use even moderately powered electrical equipment or soldering irons while you're tired.
- Don't break anything, which implies that you should ask if you're unsure of any measurement or connection
- Don't leave your projects in the RF lab. Bring them in for testing and take them when you leave. Anything Prof. Spencer finds in the lab will be dissembled and put in spare parts drawers.
- Don't take any equipment, no matter how small, out of the RF lab without checking it out from Prof. Spencer.
- Contribute to maintenance: the RF lab has an assortment of maintenance needs from keeping the inventory up to date to repairing damaged anechoic chamber tips. Part of being a user is a responsibility to help Prof. Spencer maintain the lab.
- Replace any equipment you use. The RF lab's continuing operation is 'recharge funded,' which means that users buy replacements for any parts they use. The lab also appreciates donations of parts from any finished projects.
- Make sure that only certified users use the lab. You may help a non-certified user complete a measurement, but you need to directly supervise them to ensure they don't damage equipment or break any lab rules.
You are expected to have the lab's ground rules memorized for the certification exam.
VNA Documentation
Other Documentation
- RF Basics
- Guide to SMA Cable Construction, Testing and Handling
(Courtesy of Berkeley EE142) - Outdoor Testing Guide
- Script for using USB-GPIB adapter to interface with VNA
- KiCAD files for test boards
- High Speed Measurements of 4 Layer OshPark Boards
- Simulations of SMA connector interfaces to OshPark RF Boards