1b5ca9fc3c812c6079146b8107f7f22f.ppt
- Количество слайдов: 25
Antenna Analysers Bryan, G 8 DKK
What’s in a Name? You might expect “antenna analysers” to measure antenna pattern as well as VSWR In general - they don’t! They measure VSWR in all its guises of real and sometimes imaginary parts: VSWR, Reflection coefficient (magnitude & phase), Return Loss (d. B), Impedance Z = R ± j. X
Antenna Measuring Before buying an antenna analyser consider what you do with antennas: Buy an antenna, erect it and assume it’s right Buy an antenna, erect it then check/adjust it Construct an antenna and assume it’s right Build or buy and fiddle with it to optimise it for frequency or bands or bandwidth Construct an antenna then measure and calculate matching components (per band)
Antenna Analysers Parameters that might influence choice: Standalone or work with PC Frequency Range, Stability, Resolution, Accuracy, Sweep Display size & resolution, Pixel resolution, Available measurement parameters VSWR, Return loss, Z, R, X, sign of X, phase, TDR Size, Weight, Cost
Types of Antenna Analyser There are many ways to group these analysers By type or method of display By measurement capability Frequency Range
Types of Antenna Analyser 2 Measurement Capability 1. VSWR only – SWR Indicators 2. VSWR, Z, R & X – but not sign of X 3. VSWR, Z, R & X with sign, Phase, Smith Chart (and often TDR) these are known as one-port Vector Network Analysers (VNA) 4. 2 -Port VNA - As one port plus loss measurement
Types of Antenna Analyser 3 Type of Display Analogue Meter Text only LCD (LED) Graphical LCD (LCD size) – Rectangular (X-Y) and polar (Smith Chart) displays PC screen Frequency Range & Stability L-C Oscillator, manual tuning Synthesised Frequency range affects price
Antenna Analysers VSWR Indicators
MFJ-207
You. Kits FG-01
MFJ-259 C
Analysers & Calibration Analysers with pre-calibration Most of the following analysers are provided with an in-built, full frequency range calibration Why Calibrate? Improve accuracy – drift with time & temperature, cal over narrow sweep width Calibrate at the end of a cable Calibration parts required Short, Open, Load 50Ω in same connector as analyser or cable
Palstar ZM 30
MFJ-226 (Times Technology)
Times Tech (HK) T 100+ VHF/UHF
Rig. Expert AA-54
Rig. Expert AA-230 zoom UU 9 JDR
Rig. Expert AA-600
My. Del Sark 110
Analysers with 2 Ports These analysers usually operate via a PC Measure all parameters like a 1 -port plus insertion loss. Cal at end of cable as standard They have an additional receiver port that can be included in the calibration process There is no internally stored calibration so calibration is essential as is a set of calibration parts (Short, Open, Load). Calibrations usually stored in the PC as files Not recommended as a first analyser
VNWA 3 (SDR-Kits) DG 8 SAQ
m. RS Mini. VNA Tiny
Price Comparison Model Connector Max Frequency Price MFJ-207 SO 239 30 MHz £ 99 REU AA-30 SO 239 30 MHz £ 190 You. Kits FG 01 SO 239 72 MHz £ 240 MFJ-259 C SO 239 230 MHz £ 250 REU AA-54 SO 239 54 MHz £ 280 MFJ-226 N 230 MHz £ 330 SARK 110 MCX + SMA 200 MHz £ 330 ZM 30 BNC 30 MHz £ 367 mini. VNA Tiny SMA 3000 MHz £ 380 VNWA 3 SMA 1300 MHz £ 407 REU AA-230 Z N 230 MHz £ 427 REU AA-600 N 600 MHz £ 470 REU AA-1400 N 1400 MHz £ 900
Summary If you decide to buy an Antenna Analyser: Decide what it will do for you Is it worth £ 300+ for once a year use? Are you able to borrow a unit? Match the frequency range to your requirements Choose a unit that will best match with your intended use
Websites Here are some useful websites: www. mfjenterprises. com www. rigexpert. com (recommended reading) www. mixw. co. uk (KMK) www. sark 110. com www. sdr-kits. co. uk www. miniradiosolutions. com www. timestechnology. com. hk www. arraysolutions. com
1b5ca9fc3c812c6079146b8107f7f22f.ppt