Contents I. INTRODUCTION
With increasing complexity of high speed digital circuit board and rapid development of wireless devices built-in cell phone or wireless LAN, there are numerous design and fabrication issues. Especially, these circuitry modules sometimes cause electromagnetic interference in self equipment [1] or excessive electromagnetic radiation to generate electromagnetic interference (EMI) problems. With a map of electromagnetic field intensity on the substrate [2]–[3], one can find the whole field intensity distribution around device and find out the corresponding noise source. In order to locate source of electromagnetic radiation or to predict far-field emission level, magnetic near-field measurement by magnetic field probe is a promising method. In ref. [4], an integrated RF magnetic field probe micro-fabricated using CMOS-silicon-on-insulator (SOI) technology obtains a further-miniature and high spatial-resolution function; A stripline magnetic near-field probe for high frequency band up to 10 GHz achieved an improved spatial resolution [5]; a set of orthogonal loops was proposed for a rapid E-, and circular H-fields measurement [6]; In ref. [7], a bond wired rectangular magnetic field probe, which effectively suppresses resonance behavior between probe and ground plane, was proposed to gauge much higher frequency region than conventional magnetic probe. According to requirement of electromagnetic sensor, broad bandwidth, high spatial resolution, and large isolation in sensed electrical and magnetic field are respect. On the other hand, by adding modified periodic loads to a microstrip line [8], the proposed integrated microstrip antennas not only retained good performance, but also eliminated harmonic resonances and spurious emission. Here, the geometric dimension and structure should be suitably chose to achieve desired performance.
