TEKBOX TBCCP1-3K100 Coaxial RF Current Monitoring Probe Instruction Manual

V1.0
TBCCP1-3K100
COAXIAL RF CURRENT MONITORING PROBE

Introduction

The TBCCP1-3K100 is a coaxial RF current monitoring probe, expanding the Tekbox product range of affordable EMC pre-compliance test equipment.
The probe has a 3 dB bandwidth from 3 kHz to 100 MHz and a very flat response from 9 kHz to 30 MHz. The transimpedance is characterized over the frequency range from 10 Hz to 100 MHz. The TBCCP1-3K100 is primarily designed as transducer for active loop antennas or for measurement of RF currents in coaxial cables.

The probe is equipped with N-connectors. An attachment with a ¼” thread permits connectivity to standard tripods.

Specification

Transfer impedance

Coaxial Path – Insertion loss (S21)

Coaxial Path – Matching (S11)

Application

The TBCCP1-3K100 is primarily designed as current transducer for active loop antennas. It will provide a very flat response in the frequency range from 9 kHz to 30 MHz. Combined with a 185 cm length slotted coaxial cable, it will form a passive loop antenna with a diameter of 60 cm. The magnetic antenna factor will have a value of approximately 0dBS/m. Adding a 20…30 dB amplifier will result in an antenna factor of -20 dBS/m ….-30 dBS/m. This provides sufficient sensitivity, even for standards such as CISPR11 Class A / Group 1 measured in situ, with a magnetic field strength limit of -21.5 dBµA/m in the frequency range from 20 – 30 MHz and at a distance of 30 meters. When used as transducer for a passive antenna, a typical sensitivity of -4 dBµA/m can be achieved. This would be sufficient for CISPR 14 radiated emission measurments in the frequency range from 9 kHz to 30 MHz. For more details, download the application note Loop Antenna Basics.pdf from the Tekbox website.

Typical transfer impedance table

The table below shows typical transfer impedance data of a TBCCP1-3K100 current probe. Each current probe is delivered with its corresponding measurement protocol. This data can be used for the creation of a correction file for EMCview or similar EMC measurement software. The transfer impedance in dBΩ subtracted from the analyzer reading in dBµV gives the corrected reading in dBµA. Refer to the application notes of EMCview on how to create a current probe correction file, download a file with typical data from the Tekbox website or simply select the file from the installed correction file directory.

Frequency [MHz]| transfer impedance [dBΩ]| Frequency [MHz]| transfer impedance [dBΩ]
---|---|---|---
0.00001| -40.60| 0.25| 5.16
0.000025| -34.42| 0.5| 5.15
0.00005| -28.46| 0.75| 5.15
0.000075| -24.97| 1| 5.15
0.0001| -22.47| 2.5| 5.15
0.00025| -14.57| 5| 5.14
0.0005| -8.70| 7.5| 5.14
0.00075| -5.38| 10| 5.12
0.001| -3.17| 20| 5.03
0.00125| -1.58| 30| 4.84
0.0015| -0.39| 40| 4.54
0.00175| 0.53| 50| 4.21
0.002| 1.25| 55| 3.99
0.00225| 1.83| 60| 3.76
0.0025| 2.29| 65| 3.54
0.005| 4.25| 70| 3.32
0.0075| 4.73| 75| 3.08
0.01| 4.91| 80| 2.87
0.025| 5.12| 85| 2.69
0.05| 5.15| 90| 2.52
0.075| 5.16| 95| 2.36
0.1| 5.16| 100| 2.26

Table1: Transfer impedance: 10 Hz to 100 MHz, typical data

Calibration

Tekbox coaxial RF current probes do not need a calibration fixture for the measurement of the transfer impedance.

Calculate the transfer impedance ZT using the formula below:
ZT [dBΩ] = Pin [dBm] – Pprobe [dBm] +34 dB or simply
ZT [dBΩ] = S21 [dB] +34 dB

Ordering Information

protocol 1kHz – 400 MHz

History

www.tekbox.com
TekBox Digital Solutions Vietnam Pte. Ltd.
Factory 4, F4, Lot I-3B-1, Saigon Hi-Tech Park, Tan Phu Ward, District 9, Ho Chi Minh City, Vietnam

References

• Tekbox Digital Solutions |

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