In this tutorial, we are going to learn about Basic Instruments tester in RF.
Here below are the main instruments which are using in RF testing.
- Network Analyzer
- Power Sensor
- Spectrum Analyzer
- Signal Generator
- Other RF T&M instrument
1. What is a Network Analyzer?
- A network analyzer.. Analyze networks.
- Similar to a signal generator + spectrum analyzer.
- It is very high precision instrument.
- Mostly use in LAB.
- Portable network analyzer is used in the field to test cables and antennas.
- Sometimes called VNAs : vector network analyzers.
- In the RF world, a network is a device that has one or more ‘ports’ 1. Usually components in a system. 2. Important that they work properly.
- We test a network by injecting RF into one of the port and checking, 1. How much comes back or that port? 2. How much comes out the other out?
2. What is Power Sensor?
- Sometimes, we just need to measure RF power
- A power sensor is a small, (Relatively) inexpensive way to measure RF power. 1. Just outputs a number in most cases.
- Common used in labs.
3. What is Spectrum Analyzer?
- It is range of frequencies, light and audio spectrum is humanly perceivable, RF spectrum is not humanly perceivable.
- We analyze spectrum using a spectrum analyzer.
- When we analyze spectrum’ we want to know what kind of signals (power, modulation) are present at what frequencies.
- It can be used in the lab or in the field.
What does a spectrum analyzer do?
- Basic function is power vs. frequency –1. Where is RF present and how much? 2. Power relative to other powers(dB)
- Can also demodulate signals (e.g. FM, LTE, Wi-Fi, etc.) – 1. What information is being sent? 2. How much error in the signal? 3. In this mode, spec are also called spectrum analyzer.
4. What is Signal Generator?
- A signal generator creates RF signals.
- It can be un-modulated or modulated signal.
- User can control all the parameters of a signal.
- Mostly used to test devices during design / debug.
- Primary found in LAB.
- Other RF T&M instrument:
- Communications tester – It is combination signal generator / spectrum an designed to test cell phones, Wi-Fi / Bluetooth device etc.
- EMC (Electromagnetic compatibility) – 1.Check for unintentional RF emission, 2. Check if devices are adversely affected by RF.
- Amplifier – Boost RF signal power.
- Oscilloscopes – Used mostly for non-RF electrical testing, but can also used for some RF application.