The BRAT RF Test System

Overview

The BRAT RF Test System is offered as an add-on option to the BRAT Test System. The BRAT RF Test System is housed in a rack that can be electrically and mechanically attached to the BRAT Test System. The RF Test System add-on has been designed such that when added to the BRAT, a fully integrated Test System with RF capabilities is configured. The RF Test System and its instruments are controlled by the system computer and operate in a totally automated fashion, utilizing VXI and rack-mounted instruments in an open architecture environment.


RF Stimulus Capability

The BRAT features two (2) RF synthesizers capable of -90 to +20 dBm power with AM, PM, FM, and sweep capabilities from 10 MHz to 20 GHz. Through integration with an RF Interface Unit (RFIU) equipped with the proper (optional) modules, higher power levels are achievable, as well as simulation of two tone, DSBSC, DSB, FSK, BPSK, BDPSK, OPSK, MSK, and fast frequency hopping. Accurate power and frequency management is guaranteed through stored correction factors for all RFIU paths and through system level calibration.


RF Measurement Capability

Frequency, power, PRF spectrum, modulation, and noise figure (optional spread spectrum and phase noise analysis) are available on the reconfigurable RF BRAT.


BRAT RF Instrument Specifications

Power Meter

Frequency: 100 KHz to 50 GHz (sensor dependent)
Power Range: -70 to -44 dBm (sensor dependent)
Power Sensor: 8481D Sensor
Dynamic Range: 50 dB in 10 dB steps
Accuracy Instrumentation: ±0.02 dB or ±0.5%

Power Meter Functions

Frequency:
Allows entry of test signal frequency for Cal Factor selection

Offset:
Allows power measurement to be offset by -99.99 dB to
+99.99 dB

Resolution:
Selectable resolution of 0.1, 0.01, and 0.001 dB in logarithmic mode; 1%, 0.1%, and 0.01% of full scale in linear mode

Auto Filter Mode:
The meter automatically selects the required number of averages for the chosen range and resolution

Averaging:
Selectable from 1 to 1024 readings (in powers of 2)

Duty Cycle:
Peak power representation of measured RMS power for rectangular pulses

Sensor Tables:
Allows entry and editing of up to 10 Frequency versus Cal Factor sensor tables

Save/Recall States:
Saves and recalls 10 complete E1416A operating states


Spectrum Analyzer

Frequency
Frequency Range: 3 Hz to 26.5 GHz
   
Frequency Readout Accuracy  
±[marker frequency x frequency reference accuracy + 0.25% x span + 5% + RBW +
2 Hz + 0.5 x (span/[sweep points - 1])]
 
Frequency Span
Range: 0 Hz, 10 Hz to 26.5 GHz
Accuracy: ±[0.2% x span + span/
(sweep points - 1)]
   
Frequency Reference Accuracy
Aging: ±1 x 10-7/year
Temperature Stability:
20°C to 30°C ±1 x 10-8
0°C to 55°C ±5 x 10-8
   
Sweep Time
Range:
span = 0 Hz 1 µs to 6000 s
span >/= 10 Hz 1 ms to 2000 s
   
Accuracy:
span >/= 10 Hz, sweep ±0.01% nominal
span >/= 10 Hz, FFT ±40% nominal
span = 0 Hz ±0.01 Hz nominal
   
Resolution Bandwidth (-3.01 dB Bandwidth)
Range: 1 Hz to 3 MHz (10% steps),
4, 5, 6, 8 MHz
   
Accuracy (Power):
RBW Range
1 Hz to 51 KHz ±0.5% (±0.022 dB)
56 KHz to 75 KHz ±1.0% (±0.044 dB)
82 KHz to 330 KHz ±0.5% (±0.022 dB)
360 KHz to 1.1 MHz
(< 3 GHz CF)
±1.0% (±0.044 dB)
1.2 MHz to 2.0 MHz
(< 3 GHz CF)
±0.07 dB nominal
2.2 MHz to 6.0 MHz
(< 3 GHz CF)
±0.02 dB nominal
   
Accuracy (-3.01 dB)
RBW Range
8 MHz (< 3 GHz CF) ±15% nominal
Selectivity: -60 dB/-3 dB
   
Video Bandwidth
Range: 1 Hz to 3 MHz (10% steps)
   
Amplitude Range
Measurement Range: Displayed Average Noise Level (DANL) to maximum safe input level
Input Attenuator Range: 0 to 70 dB in 2 dB steps
   
Maximum Safe Input Power
Average Total Power: +30 dBm (1 W)
+25 dBm with preamp
Pulse Power: < 10 µs pulse width, < 1% duty cycle and input attenuation >/= 30 dB
+50 dBm (100 W)
DC:
DC coupled < ±0.2 Vdc
AC coupled ±100 Vdc
   
Displayed Average Noise Level
Frequency DANL
3 Hz to 1 KHz -110 dBm nominal
1 KHz to 10 KHz -130 dBm nominal
10 KHz to 100 KHz -141 dBm
100 KHz to 1 MHz -149 dBm
1 MHz to 10 MHz -153 dBm
10 MHz to 1.2 GHz -156 dBm
1.2 GHz to 2.5 GHz -155 dBm
2.5 GHz to 3.0 GHz -154 dBm
3 GHz to 6.6 GHz -153 dBm
6.6 GHz to 13.2 GHz -152 dBm
13.2 GHz to 20 GHz -149 dBm
20 GHz to 26.5 GHz -143 dBm
   
Displayed Average Noise Level
With Preamplifier
Frequency DANL
100 KHz to 200 KHz -164 dBm
200 KHz to 500 KHz -167 dBm
500 KHz to 10 MHz -168 dBm
10 MHz to 1.1 GHz -170 dBm
1.1 GHz to 2.5 GHz -169 dBm
2.5 GHz to 3.0 GHz -167 dBm
   
Gain Compression Level
(0 dB Input Attn) < 0.5 dB for signal levels </= -10 dBm
With Preamplifier < 1 dB for signals < 0 dBm @ preamp output
   
Spurious Responses
(Mixer Level = -40 dBm)
f < 10 MHz from Carrier (-73 + 20 log N) dBc
f >/= 10 MHz from Carrier (-80 + 20 log N) dBc
(-90 + 20 log N) dBc typical
 
Second Harmonic Distortion
Band Second Harmonic
10 MHz to 400 MHz
(-40 dBm Mixer Level)
-82 dBc
400 MHz to 1.25 GHz
(-40 dBm Mixer Level)
-92 dBc
1.25 GHz to 1.5 GHz
(-40 dBm Mixer Level)
-82 dBc
1.5 GHz to 2.0 GHz
(-10 dBm Mixer Level)
-90 dBc
2.0 GHz to 13.25 GHz
(-10 dBm Mixer Level)
-100 dBc
With Preamplifier
(Input Preamp Level =
-45 dBm)
10 MHz to 1.5 GHz -60 nominal
   
Third-Order Intermodulation Distortion (TOI)
(For Two Signals, Each -30 dBm at Input Mixer with Tone Separation > 15 KHz, 20°C to 30°C)
Distortion TOI
10 MHz to 100 MHz -88 dBc +14 dBm
100 MHz to 400 MHz -90 dBc +15 dBm
400 MHz to 1.7 GHz -92 dBc +16 dBm
1.7 GHz to 3.0 GHz -94 dBc +17 dBm
3.0 GHz to 6.0 GHz -90 dBc +15 dBm
6.0 GHz to 16 GHz -76 dBc +8 dBm
16 GHz to 26.5 GHz -84 dBc +12 dBm
     
Third-Order Intermodulation Distortion
With Preamplifier
(For Two Signals, Each
-45 dBm at Preamp Input)
TOI
10 MHz to 500 MHz -15 dBm nominal
500 MHz to 3 GHz -13 dBm nominal
   

RF Synthesizers (2)

Frequency
Range: 10 MHz to 20 GHz
Resolution: 1 Hz
   
Output Power
Range: -90 dBm to +16 dBm
   
Maximum Leveled Output Power
10 MHz to 2 GHz +17 dBm
2 GHz to 20 GHz +20 dBm
   
Resolution 0.02 dB
   
Accuracy and Flatness
100 MHz to 2 GHz
Output Power Range Accuracy Flatness
-10 dBm to max. power ±1.2 dB ±0.9 dB
-10 dBm to +10 dBm ±0.8 dB ±0.5 dB
-20 dBm to -10 dBm ±1.1 dB ±0.7 dB
-60 dBm to -20 dBm ±1.1 dB ±0.7 dB
-90 dBm to -60 dBm ±1.4 dB ±1.1 dB
< 100 MHz degrade by 0.5 dB
< 2 GHz degrade by 0.1 dB
 
Harmonics < -55 dBc
Sub-Harmonics: None
Non-Harmonic Spurious: < -60 dBc
SSB Phase Noise:
(10 KHz Offset)
500 MHz -103 dBc/Hz
2 GHz -91 dBc/Hz
18 GHz -73 dBc/Hz
   
External Pulse Modulation
On/Off Ratio: > 80 dB
Minimum Pulse Width: 3.0 µs (leveled)
15 ns (unleveled)
Maximum Rise/Fall Time: < 10 ns
   
External Frequency Modulation
Rates: 1 KHz to 10 MHz
Maximum Deviation: > ±85 MHz
Maximum Modulation Index: > 180
   
External Amplitude Modulation
Depth: -20 dBm in normal mode
50 dB below max. output in deep mode
Rate: DC to 250 KHz
Accuracy: < 7% of depth

Digitizing Oscilloscope

Bandwidth: DC to 500 MHz
Maximum Sample Rate: 5 GSa/s
Maximum Input Voltage: 150 V rms @ 1 M Ohm
Vertical Resolution: 9 bits
Time Base: Range: 1 ns to 10 s full scale
Resolution: 20 ppm

RF Interface Unit (RFIU) Mainframe

Basic Configuration
8-slot wide RF mainframe (containing the necessary power supplies, motherboard, and cooling elements) and a 1-slot wide microcontroller module

Optional Configurations
RFIUs can be configured to provide an assortment of stimuli and perform a multitude of measurements including:

Stimuli

  • High Power
  • Low Phase Noise
  • Signal + Noise
  • Differential Phase
  • Spread Spectrum
  • Multipath Fade Simulation
  • Angle of Arrival Simulation
  • Noise

Measurement

  • Logarithmic Detection
  • Frequency Discrimination
  • VSWR
  • Power
  • Phase Noise (Absolute and Additive)
  • AM Noise
  • Spread Spectrum Decorrelation