Phase Noise Tester Operation Guide

BRIDZA

Table of Contents

• Hardware Connection
• Measurement Configuration
• Calibration Procedure
• Results Interpretation
• Troubleshooting

1. Hardware Connection

1.1 System Overview

┌─────────────────────────────────────────────────────────────┐
│ BRIDZA Phase Noise Tester │
├─────────────────────────────────────────────────────────────┤
│ │
│ DUT ──────────────────►│ PNT │◄──────── Reference │
│ (Device Under Test) │ │ (Ultra-Low PN Source) │
│ │ │ │
│ 10 MHz Input │ │ 100 MHz Output │
│ or │ │ or │
│ RF Input (10MHz-12GHz) │ │ RF Output │
│ │ │ │
└─────────────────────────────────────────────────────────────┘

1.2 Connection Diagram

For Source/Output Device Testing (e.g., Oscillators, Synthesizers):

 ┌──────────────────┐
 │ DUT (10 MHz) │
 │ OCXO/Rb/PDRO │
 └────────┬─────────┘
 │ BNC Cable (50Ω)
 ▼
 ┌──────────────────┐
 │ │
 │ Phase Noise │
 │ Tester (PNT) │
 │ │
 └────────┬─────────┘
 │ BNC Cable
 ▼
 ┌──────────────────┐
 │ Reference │
 │ Source │
 │ (Low-PN Rb) │
 └──────────────────┘

For Amplified DUT Testing:

 ┌─────────────┐ RF Cable ┌─────────────┐ BNC ┌─────────────┐
 │ DUT │──────────────►│ Preamplifier│───cable──►│ PNT │
 │ (High-PN │ │ (if needed) │ │ │
 │ Source) │ └─────────────┘ └──────┬──────┘
 └─────────────┘ │ BNC
 ▼
 ┌─────────────┐
 │ Reference │
 │ Source │
 └─────────────┘

1.3 Cable Requirements

Cable Selection Guidelines:

• Use phase-stable cables for critical measurements
• Match cable types on both DUT and reference paths
• Minimize cable length to reduce losses
• Avoid coiled cables (introduces phase errors)

1.4 Front Panel Overview

┌────────────────────────────────────────────────────────────┐
│ BRIDZA Phase Noise Tester │
├────────────────────────────────────────────────────────────┤
│ [POWER] [PRESET] [CAL] [RUN/STOP] FREQ: 10.000 MHz │
│ │
│ ┌──────────────────────────────────────────────────────┐ │
│ │ ████████████████████████████████████████████████ │ │
│ │ │ │
│ │ PHASE NOISE DISPLAY │ │
│ │ (dBc/Hz vs Offset Frequency) │ │
│ │ │ │
│ │ │ │
│ └──────────────────────────────────────────────────────┘ │
│ │
│ MEAS ┌─────────┐ REFS ┌─────────┐ STATUS │
│ INPUT │10MHz IN │ INPUT │REF IN │ ● PWR │
│ ● │50Ω BNC │ ● │50Ω N │ ● LOCK │
│ └─────────┘ └─────────┘ ○ CAL │
│ │
│ USB ETHERNET HDMI GPIO │
└────────────────────────────────────────────────────────────┘

1.5 Rear Panel

┌────────────────────────────────────────────────────────────┐
│ │
│ [AC POWER INLET] [FAN] [RS232] [USB] [EXT TRIG] │
│ IEC C14 ● DB9 TypeB BNC │
│ │
│ ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐ │
│ │TRIG OUT│ │10MHz OUT│ │100MHz │ │VIDEO │ │
│ │BNC │ │50Ω BNC │ │OUT 50Ω │ │OUT │ │
│ └─────────┘ └─────────┘ └─────────┘ └─────────┘ │
│ │
│ MAC: 00:1A:2B:3C:4D:5E S/N: PNT-2024-001 v2.3.1 │
└────────────────────────────────────────────────────────────┘

2. Measurement Configuration

2.1 Basic Measurement Setup

Step 1: Connect Devices

• Connect DUT output to MEAS INPUT (50Ω BNC)
• Connect reference source to REF INPUT (50Ω N or BNC)
• Power on all devices
• Allow 30-minute warm-up for best accuracy

Step 2: Configure Measurement

• Press [PRESET] to load default settings
• Set measurement frequency:

 Press [FREQ] → Enter "10" → Select "MHz"

• Verify input coupling (AC/DC):

 Press [INPUT] → Select "AC COUPLED"

Step 3: Start Measurement

• Press [RUN/STOP] to begin
• Wait for measurement to settle (typically 2-5 minutes)
• View real-time phase noise curve

2.2 Frequency Configuration

Configuring Frequency:

┌────────────────────────────────────────────────────────┐
│ FREQUENCY SETUP │
├────────────────────────────────────────────────────────┤
│ Center Frequency: [10.000000] MHz │
│ Offset Range: [1] to [10000000] Hz │
│ Resolution BW: [AUTO ▼] │
│ │
│ [ ] Prescale Mode (for >1 GHz inputs) │
│ [ ] Harmonic: [1 ▼] │
│ │
│ Input Impedance: [50Ω ▼] │
│ Input Level: [AUTO ▼] │
│ │
│ [Apply] [Cancel] │
└────────────────────────────────────────────────────────┘

2.3 Measurement Bandwidth Settings

Auto-Configure:

• Press [AUTO] to automatically set bandwidth for optimal measurement
• System will choose based on expected noise floor

2.4 Reference Source Configuration

Reference Requirements:

Reference Level Setting:

Press [REF] → Set level: +10 dBm (typical)

3. Calibration Procedure

3.1 Pre-Measurement Calibration

Purpose: Establish baseline measurement system performance

Procedure:

• Connect Calibration Reference

- Use BRIDZA supplied calibration cable

- Connect CAL OUTPUT to MEAS INPUT

- Connect same cable to REF INPUT

• Start Calibration Mode

 Press [CAL] → Select "Self-Cal"

• Wait for Calibration

- Display shows "CALIBRATING..."

- Duration: 3-5 minutes

- System measures internal noise floor

- Stores calibration data

• Verify Calibration

 Press [CAL] → Select "Cal Status"

- Check: "Cal Valid" indicator

- Check calibration date/time

3.2 Calibration Cable Compensation

For high-accuracy measurements, compensate for cable loss:

• Measure Cable Loss

- Use network analyzer

- Record S21 at measurement frequency

• Enter Cable Compensation

 Press [SETUP] → [Cable Comp] → Enter loss value

• Apply to Measurement

- System will auto-correct measurements

3.3 Environmental Calibration

For measurements affected by temperature:

• Allow Thermal Equilibrium

- Minimum 2-hour soak at test temperature

- All equipment at same temperature

• Run Environmental Cal

 Press [CAL] → [Environment] → [Temp Cal]

3.4 Calibration Schedule

Note: BRIDZA typical test data available upon request for verification.

4. Results Interpretation

4.1 Phase Noise Display

┌─────────────────────────────────────────────────────────────┐
│ TYPICAL PHASE NOISE CURVE │
│ │
│ L(f) │
│ (dBc/Hz) │
│ │ │
│ -40│ ╱╲ │
 │ │ ╱ ╲ │
│ -60│ ╱ ╲____ │
 │ │ ╱ ╲ │
│ -80│______╱ ╲_____ │
 │ │ ╲____ │
│-100│ ╲______ │
 │ │ ╲____________ │
│-120│ ╲__│
 │ └───────────────────────────────────────────────────────►│
 │ 0.01 0.1 1 10 100 1k 10k 100k 1M │
 │ Offset Frequency (Hz) │
 └─────────────────────────────────────────────────────────────┘

4.2 Reading the Phase Noise Curve

Key Offset Frequencies:

4.3 Quantitative Measurements

Single-Point Reading:

Place cursor on curve → Read L(f) value
Example: @ 1 kHz offset = -85 dBc/Hz

Integrated RMS Phase Error:

Press [MEAS] → [RMS Phase Jitter]
→ Displays integrated 1 Hz to 10 MHz (or specified range)
Typical: 0.1° to 10° RMS depending on source quality

Spot Noise Values Table:

4.4 Residual Phase Noise

For frequency distribution amplifiers and other components:

Measurement Setup:

 ┌─────────┐ ┌─────────┐
DUT ───►│ PNT │◄────────│ REF │
 │ │ │ │
 │ Channel A│ │ │
 │ Channel B│ │ │
 └─────────┘ └─────────┘

Interpretation:

• Residual PN = PN(DUT) - PN(reference)
• Negative residual = DUT adds no significant noise
• Positive residual = DUT is limiting factor

4.5 Comparison with Specifications

Pass/Fail Criteria:

Note: BRIDZA provides typical test data for reference units.

5. Troubleshooting

5.1 High Noise Floor

Diagnostic:

# Check input levels
Press [DISPLAY] → [Input Monitor]
# Verify level is in green zone (-20 to +10 dBm)

5.2 Unstable Measurement

Diagnostic:

# Enable real-time monitoring
Press [DISPLAY] → [Real-Time] → [ON]

# Check measurement repeatability
Run measurement 3 times, compare results
Variation > 3 dB indicates instability

5.3 No Signal Detected

Diagnostic:

# Check input spectrum
Press [MEAS] → [Spectrum] → [Input A]

# Verify signal present
Peak should be visible at expected frequency

5.4 Calibration Failures

Diagnostic:

# View calibration log
Press [CAL] → [Cal Log]

# Run self-test
Press [DIAG] → [Self Test]

5.5 Frequency-Specific Issues

Below 100 MHz (Baseband):

• Ensure 10MHz reference connected
• Verify input coupling (AC vs DC)
• Check termination (50Ω vs Hi-Z)

Above 100 MHz (RF):

• Use prescaler mode for >1 GHz
• Verify harmonic selection
• Check cable losses at frequency

Very Low Offset (< 10 Hz):

• Allow extended warm-up (hours)
• Isolate from vibration
• Use temperature-controlled environment

Technical Support

For additional assistance:

• Email: [email protected]
• Documentation: https://rf.bridza.com/downloads
• Knowledge Base: https://rf.bridza.com/support

Document Version: 1.0 | Last Updated: 2025