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  • 10Hz supports off-line power supplies
  • 45MHz high enough for even state of the art regulators
  • 23 Octave range
  • Low distortion for superior precision
  • 5 Ohm termination for minimum impact to loop
  • Includes attenuation to assure small signal measurement
  • cilloscopes and and Spectrum Analyzers


What's included:

J2101A Injection Transformer 10Hz - 45MHz
User manual
1 Year Warranty


The injection transformer is presently the prevalent method for connecting the network analyzer to the circuit being tested, and is primarily used for control loop stability measurements. The goal of the transformer is to inject a signal into the control loop being measured, without impacting the performance of the loop. In order to accomplish this to a reasonable degree, The transformer is isolated and therefore is capable of floating on a high voltage, such as a Power Factor Corrector (PFC), which is often close to 400VDC. Measuring voltages that exceed the voltage rating of the Bode-100 inputs require attenuation probes.

The usable bandwidth of an injection transformer is generally significantly greater than the 3dB frequency limits. In the case of the J2101A, better than 45MHz. This is because the transformer itself is outside of the measurement, leading many to incorrectly believe that the transformer is a non-critical element. The J2110A offers even greater bandwidths.

The bandwidth of the transformer is strongly related to the terminating impedance. The Bode-100, and most network analyzers, provide a 50 Ohm oscillator source impedance. Assuming this impedance the optimal termination resistor is 5 Ohms. This significantly attenuates the injection signal, which is generally beneficial, as a common error in Bode measurements is using a signal which is too large, and therefore not a small signal measurement. An added benefit of this low value is that it can generally be left in circuit at all times, simplifying the connection to the network analyzer without appreciably impacting the output voltage of the circuit being tested.


Picotest J2101A Injection Transformer 10Hz - 45MHz

  • Characteristic Rating
    Ratio 1:1
    Termination Impedance 5 Ohms
    * Usable Bandwidth 10Hz - 45MHz (Terminated into 5 Ohms)
    60Hz - 45MHz (Terminated into 50 Ohms)
    Isolation Voltage 600V
    Isolation Capacitance 150pF
    DC current 10mA
    Temperature range 0-50C
    Maximum Altitude 6000 Ft

    *Note: The upper end of the bandwidth is heavily dependent on the interconnect between the Injector and the DUT.


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