VAMP 9243 Schwarzbeck Tie Rod Antenna Stick Antenna

Introduction：

VAMP 9243 is one of the four common antenna models produced by Schwarzbeck and authorized by EUTTEST for sale, and we also call it a rod antenna or stick antenna in the antenna industry of EMC. In order to absolutely avoid the test data being affected by the RF interference brought about by the utility, power supply, voltage regulator and other power lines, the antenna has a built-in Ni-MH rechargeable battery, which can be used directly for power supply during the test, and the typical operating time of the battery is at least 50 hours.

2024 RemarksThe model number of VAMP 9243 has been upgraded to VAMP 9243 B; the parameters of the two models are the same, only the model number has been changed; VAMP 9243B will continue to use the technical parameters and related descriptions on this page, and if there is any update at a later time, we will link this model number to a new page.

Principle of a tie rod antenna or stick antenna:

Tie rod antennas and stick antennas, so named because they have only one vertical antenna rod, use the following formula for frequency and wavelength of an antenna to calculate the wavelength:

λ = C/f

• C is the speed of light ≈ 3.0*10^8 m/s
• f is the frequency in Hz
• λ is the wavelength in meters

So according to VAMP9243 upper frequency 30MHz:

Wavelength at 30MHz λ = 3.0*10^8 / 30MHz = 10 meters;

Similarly, according to the lower frequency limit of this antenna 9kHz:

Wavelength at 9kHz λ = 3.0*10^8 / 9kHz = 33333 meters;

The characteristics of the current distribution on the rod are similar to those of transmission line theory. At frequencies below about 10 MHz, the 1 m pole length is always short compared to the wavelength (λ ≥ 30 m), so the current maximum is on the ground and the voltage maximum is at the top of the pole. Since the active pole antenna has a very high input impedance, the voltage is measured at a height of 1 m below the top of the pole.

Structure of a tie rod antenna:

The antenna consists of a vertical antenna pole and an impedance matching amplifier top and bottom:

Vertical Antenna Pole: The standard length is 1 meter (other standard required pole lengths can be purchased on a custom basis by contacting EUTTEST) and can be considered short compared to the wavelengths in the frequency range 9kHz-30MHz.

Impedance matching amplifier: The impedance of the amplifier is extremely high, so the conversion factor of the antenna is independent of the frequency, the conversion factor of the antenna can be used at full frequency +10dB, the amplifier provides the antenna with very low internal noise and intermodulation interference, and the sensitive EMI test receiver can be used in the antenna's entire dynamic range.

Test product recommendations for tie rod antennas:

Basically, an active tie rod antenna or bar antenna is an electric field strength adapter. It can be combined with our magnetic field probes, e.g. FMZB 1537, to measure the electric and magnetic field strengths separately and with high sensitivity in the frequency range of 9 kHz-30 MHz. Therefore, especially in the field of automotive electronic components, the antenna fulfills the requirements of CISPR25 for radiated emission tests up to 30 MHz.

Attention:Normally you will need to mount this antenna on a metal (electrical) ground grid and take measurements in a shielded room or an airwave dark room.

Options:

VT 20dB Input Attenuator

For very high field strengths, a plug-in attenuator option is available: 20dB Input Attenuator; this reduces the input signal by 20dB before transmitting it to the amplifier below the antenna, which protects the amplifier from burn-in.

Plug-in attenuator option: 20dB input attenuator

Other options

Other options listed below need to be selected based on test standards, please contact us for a customized test solution.

• GP :Ground reference plane, 0.6 x 0.6 m
• ACS 410 : Power Adapter ACS 410
• CA 9243 B : Calibration Metering Adapter for VAMP 9243
• Opt. MIL461F bonding kit.

Technical parameters：

Graph of related technical parameters：

Noise level - using QP quasi-peak detector

radiance factor