No-Weon Kang

Field analysis of electro-optic probes for minimally invasive microwave sampling.

We numerically and experimentally investigate the field invasiveness of microwave signals using an electro-optic technique. The distortion of the standing wave voltage and pulse waveform probed by the electro-optic technique is explored through both minimally invasive external and non-invasive internal sensing configurations. First, we analyzed the continuous wave microwave field imaging on a millimeter- scale coaxial transmission line using a highly accurate and stable electro- optic scanning system. The electric field images from the microwave device are attained virtually non-invasively using a miniaturized fiber-coupled electro-optic probe. The accuracy of the field imaging associated with various probe styles is investigated by numerical analysis and experiment. Then, we analyzed the waveform of the coaxial transmission line up to 50 GHz using a pulsed electro-optic system with an external probe set. Finally, the invasive analysis was extended to the sub-millimeter-scale on-wafer coplanar waveguides, where the voltage waveforms are measured using a minimally invasive external probe as well as an internal wafer probe for non-invasive sampling.

Characterization Method of Electric Field Probe by Using Transfer Standard in GTEM Cell

In this paper, we introduce a simple and wideband characterization method for electric field probes using a transfer standard. As a transfer standard, a thin disk-type reference probe that can operate from 50 to 1000 MHz is used and calibrated using a micro transverse electromagnetic (mu-TEM) cell. A gigahertz transverse electromagnetic (GTEM) cell is used to generate a reference electric field. It has been shown that the uncertainty of the proposed method can be increased due to the imperfection of the field condition in the cell. According to the measurement result, the proposed characterization method for the electric probes agrees within 6.3%, compared with the method that uses the TEM cell and standard antennas in a fully anechoic chamber.

Field-calibrated electro-optic probe using interferometric modulations

A very concise field-calibrated electro-optic probe using interference of modulated beams is presented. A model for interferometric electro-optic sensing with a sensor probe is proposed, utilizing the interference fringing slopes and field-induced electro-optic phase retardations. The sensing dynamic range is experimentally explored by investigating the modulation slopes and retardations with respect to the probe beams polarizations. The probe shows a dynamic range ≥45 dB over the microstrip lines. This sensitivity is acceptable for realizing electric field imaging of radiative electronic devices. The absolute sensitivity of the probe is also determined with a micro-TEM cell that generates accurate electric fields with calculable strength for probe calibrations.

Indirect Contact Probing Method for Characterizing Vertical Interconnections in Electronic Packaging

This letter proposes a new indirect contact probing method to characterize vertical interconnections without contact damage. At the first step of the proposed technique, multiple one-port calibration measurements should be performed to characterize the contactor layer between the probe pads and the device-under-tests (DUTs). The characteristics of the actual vias as the DUTs are then extracted from indirect-contact measurements by de-embedding the contactor layer. In simulations and experiments at frequencies range from 2.5 to 18 GHz, we have verified via defects can be successfully identified from the indirect-contact measurements.

Intercomparison of Standard Gain Horn Antennas at

An intercomparison of two W-band (75-110 GHz) standard gain horn antennas of nominal gains 24 and 27 dB has been performed at the Korea Research Institute of Standards and Science (KRISS), National Physical Laboratory (NPL), and National Institute of Standards and Technology (NIST). The measurement parameters for this comparison are the power gain and complex reflection coefficient of the traveling standards measured at 75, 95, and 110 GHz, and, as an option, the swept-frequency power gain measured over the frequency range of 75-110 GHz with a finite frequency step. All participants performed the fixed-frequency antenna measurements, whereas the swept-frequency antenna measurements were carried out by the NPL and the NIST. This paper describes the comparison and its measurement results with uncertainties. Generally, the agreement between the results in all the measurements is within the uncertainty of each participant, except for fixed-frequency gain results of the high-gain antenna at 110 GHz, reflection coefficient results at some fixed frequencies, and swept-frequency gain results of the high-gain antenna in the low- and high-frequency regions of the W-band.

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This paper presents a disk-type small reference probe operating up to 1 GHz as an electric field transfer sensor. The probe is calibrated using a mu-TEM cell and demonstrates a wide useable electric field strength range. Design and calibration methods are presented. The probe is suitable for testing and comparing the performances of reference field generation systems, both TEM cells and antennas. As an application, a technique for measuring the antenna gain is proposed and applied to open-ended waveguide antennas

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A W-band waveguide noise measurement system has been developed for noise temperature (NT) standards. The system consists of two standard noise sources and a waveguide radiometer. A horn-type cryogenic noise source operating at the liquid nitrogen temperature and an ambient temperature termination have been employed as standard noise sources. To measure noise power radiated from the noise sources including a device under test, a total-power waveguide radiometer has been constructed and its performance has been evaluated. Measured NT of a commercial waveguide noise source is presented with the measurement uncertainty of 0.10-0.13 dB (k=2) in W-band.

Fabrication of Small Reference Probe and Its Application

A cryogenic noise reference standard consists of an antenna, a cavity, an electromagnetic absorber, and a liquid nitrogen container. The horn antenna is installed at the upper part of the cavity to measure the thermal noise radiated from the absorber carefully placed at the bottom of the cavity. By filling liquid nitrogen to an appropriate level the electromagnetic absorber is maintained at approximately 77 K. In this paper, some design considerations are discussed to minimize the diffraction from the internal surface of the horn antenna. Using the resultant dimension of the horn, the attenuation of the overall horn antenna is evaluated to be 0.033 dB to 0.037 dB in the frequency range of 75 GHz to 110 GHz. The calculated attenuation with other relevant parameters is used to obtain the calculable output noise temperature of the cryogenic noise reference standard.

A Thermal Noise Measurement System for Noise Temperature Standards in

In this paper, an indirect contact probing method for via arrays is proposed. The proposed method characterizes via arrays without contact damage from probe tips, and it does not require additional control and sensor electronics. To execute the indirect contact method, firstly, multiple measurements on specially designed calibration vias are performed to obtain the dielectric contactor characteristic. The characterized contactor layer is de-embedded when the actual via arrays as the device-under-tests (DUTs) are extracted. In simulations at frequencies ranging from 800 MHz to 25 GHz, it is confirmed that defects on via arrays can be successfully identified from the indirect-contact probing.

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An APMP key comparison of power gain for Ka-band (26.5 GHz - 40 GHz) horn antennas has been being carried out between KRISS and NMIJ. This paper describes the comparison and its progress so far. Measurement results will be presented at the conference.