Jun Fan

Bio: Jun Fan is an academic researcher from Missouri University of Science and Technology. The author has contributed to research in topics: Equivalent circuit & Printed circuit board. The author has an hindex of 36, co-authored 482 publications receiving 5641 citations. Previous affiliations of Jun Fan include Ulsan National Institute of Science and Technology & University of Missouri.

A 20 GHz Landing Probe Design Based on Pogo-pins

Abstract: A landing probe design is proposed in this paper based on pogo-pins. Landing probes are usually used to obtain TDR and S-parameters of the device under test (DUT) so that the performance of the DUT can be evaluated. This design has two major advantages. First, it is durable. Second, it can be easily integrated into automated testing systems. The designed probe works well up to 20 GHz, which is validated by measurement.

The application of spark gaps on audio jack for ESD protection

Abstract: ESD strikes can be suppressed by placing ESD protection devices along ESD current paths. As primary ESD protection on PCBs, spark gaps are cheap and take little space, but the breakdown voltage is not low enough and the lag time can be too long to protect the circuit. The effect of adding carbon and non linear polymers to the spark gap is investigated in this paper.

Design of on-chip linear voltage regulator module and measurement of power distribution network noise fluctuation at high-speed output buffer

Abstract: By applying on-chip linear VRM, PDN inductance is greatly decreased and PDN resonance peak disappears, which is usually generated by PCB/PKG inductance and on-chip capacitance. To confirm, we design an application circuits which have on-chip linear voltage regulator module (VRM) with aggressor and victim buffer. We validate the advantages of on-chip linear VRM by measuring fabricated chip in this research. Moreover, we show PDN self-impedance at output buffer by simulation with designed PCB's S-parameter, and eye-diagram power fluctuation up to 1 Gbps.

Wideband characterization of LCD baseband noise modulation for RF interference in mobile phones

Abstract: A wideband measurement technique to characterize radio frequency (RF) interference caused by a liquid crystal display (LCD) baseband noise modulation is proposed. The LCD noise in baseband frequency range modulated with the Tx carrier signal of cellular communication interferes with the Rx signal, resulting in a RF receiver desensitization problem. Since the frequency offset between the Tx and Rx bands is small (several tens of MHz), a high Tx band rejection filter is essential to characterize the relatively small modulation noise with small frequency offset along with the strong Tx carrier signal. A typical solution is to use a duplexer, which only works for the dedicated communication band and, thus, a narrow band. The proposed measurement technique utilizes a 180° hybrid coupler and reflection cancellation to obtain high Tx band rejection without any frequency limited components. In addition, another reflection cancellation method is demonstrated for a large offset frequency case.

Special Section on Wireless EMC and Wireless OTA Measurements

Abstract: Wireless technologies are commonly integrated into various electronic designs. Electromagnetic compatibility (EMC) issues including receiver desensitization, Electrostatic discharge (ESD), modulation, intermodulation, and measurement methodologies for wireless over-the-air (OTA) performance are important to EMC and testing engineers. With the rapid development of Internet of Things (IoT) and future 5G wireless technologies, our society faces both significant challenges and opportunities. We believe that this Special Section provides an important opportunity for the EMC industry and academic community to overview the technology trends, understand the aspects applicable to wireless EMC, and review progress and directions.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

IEEE Transactions on Microwave Theory and Techniques and Antennas and Propagation Announce a Joint Special Issue on Ultra-Wideband (UWB) Technology

Abstract: Before the emergence of ultra-wideband (UWB) radios, widely used wireless communications were based on sinusoidal carriers, and impulse technologies were employed only in specific applications (e.g. radar). In 2002, the Federal Communication Commission (FCC) allowed unlicensed operation between 3.1–10.6 GHz for UWB communication, using a wideband signal format with a low EIRP level (−41.3dBm/MHz). UWB communication systems then emerged as an alternative to narrowband systems and significant effort in this area has been invested at the regulatory, commercial, and research levels.