Design And Numerical Analysis Of Tem Cell Used For IC Radiated Emission Test

TEM (Transverse Electromagnetic) cell is recommended to measure the radiated emissionfrom IC (integrated circuit) radiated emission (RE) for the frequency from150kHz to1GHz byIEC61697-2standard. With the fast development of compact size, high density, and high speedfor ICs, the radiated emission measurement is becoming more and more important. Themeasurement frequency of RE is ever-increasing, by now3GHz is becoming popularrequirement for communication product. TEM cell used for the measurement of ICs is facedmany challenging problems.The performance parameters, extension of frequency-band and structure design of TEM cellwere investigated. The numerical methods for calculating the characteristic impedance, fielddistribution, higher order mode cut-off frequencies and resonant frequencies of TEM cell weredescribed. The boundary element method (BEM) was used for analyzing the characteristicimpedance and quasi-static field distribution of TEM cell, while the software based on finiteelement method was adopted for simulating higher order modes, resonant frequencies andtransmission performances (such as S parameter and voltage standing wave ratio). The TE waves(H waves) having significant influences on perpendicular polarization property of TEM cell, andH waves have close relation with transverse current, so the transverse current can be restrainedthrough cutting longitudinal slots, and therefore the TE modes can be restrained. In the thesis theeffects of longitudinal slots, which is located on external and internal walls of TEM cell, onhigher order modes and resonant were analyzed. Above all, a novel wide frequency bandminiature TEM cell was provided. The bottom of the miniature TEM cell is opened, and the ICcan be directly place into the cell, no special PCB (printed circuit board) is needed. Theminiature TEM cell have many advantages, for example, it’s more simple to measure, withhigher frequency band, can be conveniently carried and cost saving. Finally, the key techniquesof TEM cell design such as impedance match, shielding, antisepsis and antisepsis, structuredesign, and so on were discussed.The research results show that the upper limit frequency of TEM cell can be raised to2GHzby slotting method; for the novel miniature TEM cell the upper limit frequency can be up tomore than3GHz; the design method of inner conductor proposed in this thesis can efficientlyimprove the impedance match performance, therefore improve the performance of transmissionsuch as voltage standing wave ratio.