Agilent Technologies 54835A, 45A, 46A To test bandwidth, Specification Equivalent Time, Real Time

Chapter 3: Testing Performance

To test bandwidth

To test bandwidth

This test checks the bandwidth of the oscilloscope. The Agilent 54845A bandwidth at 1.5 GHz and the Agilent 54846A bandwidth at 2.25 GHz oscilloscopes are checked using aliasing since the trigger specification of these oscilloscopes is 1 GHz. The 1.5 GHz or the 2.25 GHz signal is viewed with a time/division setting of approximately 50 ∝s/div where the on-screen display is an untriggered sinewave that appears to be at a lower frequency, however the vertical response of the amplifiers is correct. The Agilent 54835A bandwidth at 1.0 GHz and 500 MHz of all three models is checked normally.

Specification

Equivalent Time:

50Ω: 2.25 GHz (Agilent 54846A), 1.5 GHz (Agilent 54845A), 1.0 GHz (Agilent 54835A)

1 MΩ: 500 MHz (with Agilent 1161A probe)

Real Time:

50Ω: for Agilent 54846A — 2.25 GHz (2-channel mode), 1.0 GHz (4-channel mode)

50Ω: for Agilent 54845A — 1.5 GHz (2-channel mode), 1.0 GHz (4-channel mode)

50Ω: for Agilent 54835A — 1.0 GHz (2-channel mode), 500 MHz (4-channel mode)

1 MΩ: 500 MHz (with Agilent 1161A probe)

Equipment Required

Equipment	Critical Specifications	Recommended Model/Part
Signal Generator	10—2250 MHz at ≈200 mVrms	Agilent 8664A
Power Meter/Sensor	1—1.5 GHz ±3% accuracy	Agilent EPM-441A/8482A
Power Splitter	outputs differ by <0.15 dB	Agilent 11667A
Cable	Type N (m) 24 inch	Agilent 11500B
Termination	50Ω, BNC Connectors	Agilent 10100C
Adapter	Type N (m) to BNC (m)	Agilent 1250-0082
Probe	No Substitute	Agilent 1161A
Probe Tip Adapter	1160 Series to BNC	Agilent 5063-2143

Equivalent Time Test

1Connect the equipment.

a With the N cable, connect the signal generator to the power splitter input. Connect the power sensor to one output of the power splitter.

b With an N-to-BNC adapter, connect the other splitter output to the channel 1 input.

2Press Default Setup to set the oscilloscope to default conditions.

3Select Acquisition from the Setup menu. Select Equivalent Time sampling mode. Click Close. Select Display from the Setup Menu. Unselect Connect Dots mode. Click Close.

4Set the vertical scale for Channel 1 to 100 mV/div using the knob. Select 50Ω input impedance.

5Set the sweep speed to 50 ns/div using the horizontal sweep speed knob.

6 Set the signal generator for 10 MHz at +5.0 dBm.

The signal on the oscilloscope screen should be about five cycles at six divisions amplitude.

Bandwidth Check Limits

Do not exceed 6 divisions when making the bandwidth check.

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