Network Analyzer Terminal Scalar Network Analyzer

Dave Collins – AD7JT George Heron – N2APB

Poor Ham’s Scalar Network Analyzer (PHSNA)

With Network Analyzer Terminal (NAT)

TERMINAL (NAT)

POWER READINGS (dB)

< SERIAL INTERFACE >

SCAN PARAMETERS

LOGARITHMIC RF POWER METER (AD8307)

POWER LEVEL RF OUT

ARDUINO-BASED MICROCONTROLLER DEVICE UNDER TEST (DUT)

FREQ RF IN

DIGITALLY CONTROLLED SIGNAL GENERATOR (AD9850/51) https://groups.yahoo.com/neo/groups/PHSNA/info

Features

• Handheld graphic terminal for display and control of the PHSNA • 3.2”, 240 x 320, 16-bit color graphic LCD display & touch panel • User-friendly operator interface • Field upgradable firmware • Serial port connection to PHSNA (digital UART 3.3V) • Keyboard input for control of SSNA menu system • 32KB EEPROM for persistent storage (settings and options) • 14 Macros (in EEPROM) for storing operating parameters • PLX-DAQ (Excel) mode for test automation and PHSNA compat.

• Compatible with standard and enhanced PHSNA f/w versions • Simplified calibration (no curve fitting required) • Measurement & Plot Capabilities (v1.0):

- Testing and evaluating filters - Measuring crystal parameters - Return Loss Measurement - VSWR and antenna tuning - Continuous/repeated operation options

• SD Card mass storage up to 1 GB provides:

- FAT16 file system compatibility - Subdirectory support for easy file management - Data spooling and playback - Calibration data storage and reloading - Direct data exchange with Windows and Linux apps - Easy and efficient firmware upgrades - DOS –like commands to manage and playback data files

Specifications

PCB:

4.47" x 3.31"

Enclosure:

4.82" x 3.77" x 1.39"

Data rates:

1.2 to 19.2 kbaud

Power:

12V DC @ 120ma (typ) (330ma for NACT with DDS-60)

Weight:

7 oz (approx)

Display module - under $20 on eBay:

 240 x 320 Pixel (QVGA), 16 bit color, 3.2” LCD   SSD1289 display controller Resistive touch screen with ADS7843 controller    SD Card socket Pads and interconnect for serial (SPI) EEPROM Single, 40-pin interface connector

Basic NAT Block Diagram

(Versions 1 and 2)

Menu Mode screen shots

1 ENTER

Enter

PLX Mode screen shots

F1 SPACE

Scroll Lock

DOS Mode screen shots

Escape

touch touch

Y

RF IN

Optional PC Application

< SERIAL INTERFACE >

Scalar Network Analyzer (SNA) DEVICE UNDER TEST (DUT)

RF OUT

NAT-SNA: NAT-Scalar Network Analyzer

Block Diagram (Version 4)

NACT to SNA conversion RF Power Meter by Dick Faust, K9IVB http://www.k9ivb.net/RF_Power_Meter/

Scroll Lock

 RF Power Meter Mode  Primarily intended for QRP applications  Power reading taken about 200 times/second (every 5 ms)   100 dBm range, use attenuators to shift the range DDS used only for calibration  Three Power Meters Displayed  Current power reading (10-point running average)   Average Power (200-point running average) Peak Power (updated every 200 samples)

P Ctrl-G Apply RF

Antenna analysis with Return Loss Bridge (RLB)

RF INPUT (FROM DDS)

50  10T-Bifilar (FT37-43) 50 

RESONATING DUT (e.g., antenna)

50 

RETURN LOSS (TO RF POWER METER) RETURN LOSS BRIDGE

Antenna analysis with Return Loss Bridge (RLB)

Crystal Characterization & Matching

RF OUT

-3dB Attenuator 9.1

150 9.1

10T-Bifilar (FT37-43)

CRYSTAL SOCKET

10T-Bifilar (FT37-43) -3dB Attenuator 9.1

150 9.1

RF IN CRYSTAL TEST FIXTURE

Crystal Characterization & Matching

(cont.)

Crystal Characterization & Matching

(cont.)

References: http://www.midnightdesignsolutions.com/nat https://groups.yahoo.com/neo/groups/NAT-SNA/info https://groups.yahoo.com/neo/groups/PHSNA/info Dave [email protected]

and George [email protected]

QUESTIONS?

COMMENTS?

CRITIQUES?

 Time for a little math       Gain ratio = P out /P in Gain (dB) = 10 log(P out /P in ) Gain (dBm) = 10 log(P out /.001) = 10 log(P out x 1000) = 10 (log(P out ) + log(1000)) = 10 log(P out ) + 30 Short circuit gain = 10 log(P in /P in ) = 10 log(1) = 0 for any P in Gain (dBm) = 10 log(P in ) - d where: P in = power meter reading d = short circuit gain reading DDS output level varies with frequency (due to sin(x)/x sampling effect) therefore d is a function of frequency: d(f)