Electromagnetic Interference (EMI) of System-on-Package (SOP)

Electromagnetic interference (EMI) issues are expected to be crucial for next-generation system-on-package (SOP) integrated high-performance digital LSIs and for radio frequency (RF) and analog circuits. Ordinarily in SOPs, high-performance digital LSIs are sources of EMI, while RF and analog circuits are affected by EMI (victims). This paper describes the following aspects of EMI in SOPs: 1) die/package-level EMI; 2) substrate-level EMI; 3) electromagnetic modeling and simulation; and 4) near electromagnetic field measurement. First, LSI designs are discussed with regard to radiated emission. The signal-return path loop and switching current in the power/ground line are inherent sources of EMI. The EMI of substrate, which work as coupling paths or unwanted antennas, is described. Maintaining the return current path is an important aspect of substrate design for suppressing EMI and for maintaining signal integrity (SI). In addition, isolating and suppressing the resonance of the DC power bus in a substrate is another important design aspect for EMI and for power integrity (PI). Various electromagnetic simulation methodologies are introduced as indispensable design tools for achieving high-performance SOPs without EMI problems. Measurement techniques for near electric and magnetic fields are explained, as they are necessary to confirm the appropriateness of designs and to investigate the causes of EMI problems. This paper is expected to be useful in the design and development of SOPs that take EMI into consideration

A Case of Monostotic Fibrous Dysplasia of the Temporal Bone Asso­ciated with Epileptic Seizure

An 11-year-old male with monostotic fibrous dysplasia of the left temporal bone was reported. At the age of seven years, the patient began having epileptic attacks, and a bony swelling of the left temporal region was noticed by his mother. Roentgenologically, there were almost thorough osseous obstruction and osseous proliferation of the external auditory canal and pars petrosa, respectively. Audiologic examinations indicated gradual functional disturbance based on the affected internal ear. A total of 20 cases with monostotic fibrous dysplasia of the temporal bone reported between 1946 and 1980 was analyzed, and the association of fibrous dysplasia and epilepsy was discussed.</p

Prospect of cytologic diagnosis for malignant melanoma in the maxillary sinus

Two cases of malignant melanoma arising in the maxillary sinus are reported. Cytological examination of the solution obtained by local washing through the sinus puncture identified numerous melanoma cells together with melanophages. The cases were then scheduled for well-planned, preoperative treatment. The cytological criteria for diagnosing malignant melanoma are outlined, and the cytological approach is stressed as a valuable diagnostic procedure for early detection of malignant tumors and surveillance of postoperative recurrence, especially in paranasal sinuses.</p