Conference Paper

Active probes for creating H-field probes for flat frequency response

Electr. & Comput. Eng., Missouri Univ. of Sci. & Technol., Rolla, MO, USA
DOI: 10.1109/ISEMC.2009.5284635 Conference: Electromagnetic Compatibility, 2009. EMC 2009. IEEE International Symposium on
Source: IEEE Xplore

ABSTRACT This paper presents an approach to obtain a flat frequency response from the first order derivative behavior of an electrically small loop and electrically short electric field probe by using them in combination with active oscilloscope probes. An H-field probe made in flex circuit technology was designed to operate up to about 5 GHz. These probes have loop dimensions as small as 3 times 3 mil and trace widths in the order of 1.75 mils. The H-field probe terminals are connected to the differential amplifier of the active oscilloscope probe which functions as an integrator to achieve a flat frequency response. The integrator behavior compensates for the first order derivative response of the flex circuit probes. The E-field probe utilizes the high input impedance of the browser attached to the active probe for achieving a flat frequency response.

Full-text

Available from: Kuifeng Hu, Jun 17, 2014
0 Followers
 · 
113 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Closed-form expressions for transient power distribution network (PDN) noise caused by an IC switching current are derived for a PDN structure comprised of traces with decoupling capacitors. Criteria for identifying a dominant decoupling capacitor for an impulse switching current are also proposed. The derived PDN noise expressions are validated with measurements of currents at both local and bulk capacitors, the PDN impedance, and the total voltage noise in an operating consumer device.
    IEEE Transactions on Electromagnetic Compatibility 10/2012; 54(5):1112-1124. DOI:10.1109/TEMC.2012.2194786 · 1.35 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A current probe was designed to measure ball currents in a Ball-Grid-Array (BGA) package via magnetic induction. This probe, which is based on a Rogowski coil structure, is manufactured in a four-layer flex circuit. Very tiny feature sizes, such as 2 mil buried micro vias and 2 mil trace widths/clearances, push the limit of the flex-circuit fabrication process technology. This design allows the current of a ball in a 1-mm pitch BGA package to be measured. It can also be migrated to package with smaller pitch if the fabrication process allows. This probe is practical for engineering applications as a result of three major advantages. It operates in a broadband from 10 to 3 GHz. The probe can be relocated to different balls and no special printed circuit board is needed. The probe shows acceptable shielding effectiveness of the unwanted fields caused by adjacent balls or sources. In conjunction with both a differential amplifier and an active oscilloscope probe, the output signal is sufficiently amplified to overcome the noise figure of the oscilloscope. This allows time domain measurements. Moreover, a frequency-domain data processing program was developed for correcting the probe's frequency response and reconstructing the time domain waveform. The probe is validated against analytical calculation, and full-wave simulation; it is characterized with the aid of circuit modeling. The probe's functionality is finally demonstrated with a field-programmable-gate-array test board.
    IEEE Transactions on Instrumentation and Measurement 12/2013; 62(12):3323-3332. DOI:10.1109/TIM.2013.2272863 · 1.71 Impact Factor