TBMDA4B Modulated Power Amplifier

The TBMDA4B modulated wideband power amplifier is designed in order to create an inexpensive signal source for immunity testing of electronic building blocks and products. It is designed to be driven by the tracking generator output of spectrum analyzers. With an input power range of -20 dBm…-10 dBm, it can boost the output power of a tracking generator up to 5W. With a frequency range from 100 kHz to 75 MHz, it is an ideal complement to the TBMDA3, which covers 10 MHz to 1 GHz.

The TBMDA4B is ideal to drive Tekbox near field probes in order to find the sensitive spot of an electronic circuit or to create electric fields up to 550V/m when driving the Tekbox TEM Cell TBTC0, 300V/m when driving the TBTC1, 150V/m when driving the TBTC2 or 100V/m when driving the TBTC3. Test signals for immunity testing can be CW, AM or PM modulated. Consequently, the TBMDA4B provides built in modulation capability to generate 1 kHz AM or PM signals. In PM mode, the TBMDA4B can also generate a 217 Hz Signal with 12.5% duty cycle in order to simulate mobile phone TDMA noise.

FEATURES

  • CW amplifier (modulation off)
  • 1 kHz, 80% AM modulation
  • 1 kHz, 50% duty cycle pulse modulation
  • 217 Hz, 12.5% duty cycle pulse modulation

SPECIFICATIONS

Input / Output: 50 Ohm, N female
Supply Voltage range: 110 V…240 V
Supply power consumption: 20 W
Operating temperature range: -20°C to 50°C
Frequency range: 100 kHz – 75 MHz
Saturated output power @ 100 kHz / Pin = -10 dBm: 36.6 dBm (4.6W) typ.
Saturated output power @ 1 MHz / Pin = -10 dBm: 37.6 dBm (5.8W) typ.
Saturated output power @ 10 MHz / Pin = -10 dBm: 37.6 dBm (5.8W) typ.
Saturated output power @ 35 MHz / Pin = -10 dBm: 37.1 dBm (5.1W) typ.
Saturated output power @ 75 MHz / Pin = -10 dBm: 36.6 dBm (4.6W) typ.
Saturated output power @ 100 MHz / Pin = -10 dBm: 31.6 dBm (1.4W) typ.
1dB output compression point @ 1 MHz: +35.7 dBm typ.
1dB output compression point @ 35 MHz: +34.8 dBm typ.
1dB output compression point @ 75 MHz: +34.1 dBm typ.
2nd harmonic, 35 MHz, Pout=36dBm: < – 18 dBc typ.
2nd harmonic, 35 MHz, Pout=30dBm: < – 21 dBc typ.
3rd harmonic, 35 MHz, Pout=36dBm: < – 19 dBc typ.
3rd harmonic, 35 MHz, Pout=30dBm: < – 35 dBc typ.
Total harmonic distortion:
5.9% @35MHz, Pout=27dBm typ.
8.4% @35 MHz, Pout=30 dBm typ.
12.3% @35 MHz, Pout=33 dBm typ.
18.1% @35 MHz, Pout=36 dBm typ.
Third order intercept point:
+53dBm, @25 MHz, ∆ f = 200kHz typ.
Noise figure: @35 MHz: 7.2 dB
Internal modulation frequency AM: 1 kHz ±20%
Internal modulation frequencies PM: 1 kHz ±10%, 217 Hz ±20%
Duty cycle, PM: 50% ±10% @ 1 kHz; 12.5% ±20% @ 217 Hz

APPLICATION

  • general purpose power amplifier
  • signal source for immunity testing, driving near field probes
  • signal source for immunity testing, driving TEM Cells

LINKS AND REVIEWS

EDN Blog immunity testing using Tekbox modulated amplifier

A pre compliance immunity tutorial by Dr. Min Zhang of Mach One Design, an engineering consulting firm (www.mach1design.co.uk) based in Oxford, UK