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Z Technology, Inc.

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World Headquarters, Beaverton, Oregon, USA – PowerPoint PPT presentation

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Title: Z Technology, Inc.

1
World Headquarters, Beaverton, Oregon, USA
2
Our business

Design and Manufacture of RF coverage measurement
and mapping instrumentation
Emphasis on digital and analog television
coverage measurement
Specific expertise in automated RF measurement
and analysis of DTV quality of service

3
Our television customers

Transitioning to 8VSB digital service
Operating analog and digital plants
New transmission formats
New power levels
New channel assignments
New antenna locations
New government regulations
Cost and people constrained

4
Antenna Patterns

Not always as you would expect

6.5 miles from 1000 AAT
Horizontal Gain Vertical Angle
Gain
Oded Bendov / Krishna Praba, Television
Engineering Handbook, Jerry Whitaker
5
Z Technology measurement systems

Address specific measurement needs
documentation
identification
acceptance
confirmation
resolution

6
DSS5800 DTV measurement system
7
DSS5800 DTV measurement system
Programmable field strength meter
8VSB data demodulator
GPS Receiver
Power and Distribution
Laptop Windowstm PC
AC DC
8
DSS5800 DTV measurement system
Programmable field strength meter
8VSB data demodulator
GPS Receiver
Power and Distribution
Laptop Windowstm PC
AC DC
9
DSS5800 DTV measurement system
Programmable field strength meter
8VSB data demodulator
GPS Receiver
Power and Distribution
Laptop Windowstm PC
AC DC
10
DSS5800 DTV measurement system
Programmable field strength meter
8VSB data demodulator
GPS Receiver
Power and Distribution
Laptop Windowstm PC
AC DC
11
Three measurement techniques

1. Drive testing
rapid accumulation of data
identification of problem coverage areas
2. Calibrated testing
used to validate more general data
communicates very specific values
3. On-site testing
detailed evaluation of local conditions

12
Drive Testing

Rapid accumulation of coverage data
Calibrated measurement equipment
7 ft. antenna height, on roads
Automatic capture and recording
Identification of problem areas
Relative to previous runs
Poor signal coverage
Changes in coverage

13
Drive Test Considerations

Equipment configuration
Antenna, Power, Mounting, Calibration
Convenience and Safety
Environment
Location, Obstructions, Reflections
Operator interface
Driver Distraction, Information Displays
Setup Automatic Collection of Data

14
Mobile Test Antennas

Horizontal dipole
General direction towards
transmitter
Magnet mount, 24 above roof
surface
Calibrated antenna factors for dBuV/m
Vertical sampling antenna
Mag mount 1/4 wave vertical
antenna
Not true to horizontal component
Characterized

15
Mobile Test Antennas

Omnidirectional antennas
Generally lower gain, uncalibrated
Subject to multipath distortions
Rotators
Dipoles are broad pattern
Just need a general direction
Beware of distracting driver

16
Antenna Correction Factors

Measured correction factors supplied by antenna
manufacturer
Add antenna factor plus cable loss to receiver
reading in dBuV to convert to field intensity in
dBuV/Meter.
Example
Antenna Correction Factor 16.0 dB/m
Cable loss .9 dB
Meter Reading 44.0 dBuV
Field Intensity 60.9 dBuV/meter

17
Calibrate Antenna Setup

Mount antenna and adjust element length for
frequency as indicated in manufacturers table
Connect to measurement equipment with calibrated
cable
Add antenna correction factor for operating
frequency and calibrated losses
Enter system correction factor into meter or PC
application software
Meter or application will read field intensity in
dBuV/m

18
Multiple Frequency Testing

Same band, one antenna
Factory antenna factors
Element length vs. frequency vs. factor
Characterizing for multiple frequencies
Multiple Antennas
Power combiners
Filters
System characterization

19
Multiple Antennas
20
Calibration Procedures

Equipment certification
NIST traceable antennas, cables, field strength
meter
Secondary reference
Equipment setup
30 ft. antenna height vs. vehicle rooftop
Antenna factors recorded with data

21
Drive Test Procedure

Set up job
Frequencies
Antenna factors
Signal types
Adjust antenna direction
Spectrum display
Sample measurement
Start Drive Test
Hit record
Drive the route

22
DVB-T Spectrum data display
23
8VSB Spectrum data display
24
(No Transcript)
25
Operational Precautions

Do not operate while driving
Be aware of antenna orientation
Stop and enter comments where appropriate
Analyze recorded data later

26
The Drive Test

Set up the job for signal types and frequencies
Click F1 Sample to check the reception
Click F3 Record Continuous
Drive until direction changes more than 30
degrees stop and adjust antenna direction
Click F4 Stop Measurements
Take a break and look at the data

27
Automatic data recording

Analog records all setups, time, location,
direction of travel, peak power, antenna factors,
frequencies, etc.
Digital adds wideband parameters integrated
power, etc.
DTV systems add data from the digital decoder
sync/eq locks, tap values, etc.
Clear text data files are easy to read and export
to other applications

28
Clear-text Data File
29
Analyzing the data