摘要:

A longitudinal slot at the centre of the broad wall of a rectangular waveguide in the presence of one or two vertical strips has been analysed. The combination is excited by the dominant TE01mode, and the slot radiates externally. The effect of finite thickness of the waveguide walls has been taken care of by treating the slot as a stub waveguide. The coupled integral equations are solved using Galerkin's technique. The resultant coefficients are used to compute the dominant mode scattering parameters and hence the equivalentT-network. The possibility of obtaining a resonant condition for the radiating centred slot–strip combination has been established. Design data derived in this study eliminate the need to gather initial input data experimentally.

DOI:10.1049/ip-h-2.1993.0021

出版商:IEE    

年代:1993

数据来源: IET

摘要:

A triple modulation technique, applicable to microwave cavity spectrometers, is described, which enables Stark, Zeeman, double resonance or cavity modulation in the cavity gas cell to operate at a relatively low frequency, while satisfying the criterion that the microwave crystal detector should operate at a relatively high frequency. This technique is such that the microwave source is frequency double-modulated by means of sweeping signal of frequencyf1and a relatively high-frequency sinusoidal signal of frequencyf2applied to a tuning varactor, while an additional relatively low-frequency modulation such as Stark, Zeeman, double resonance or cavity modulation (frequencyf3) is applied in the cavity gas cell. The low-frequency modulation signal (f3), which contains the salient information of the analyte gas, is carried by the high-frequency signalf2, the former being extracted and amplified by a series of filters, demodulators and tuned amplifiers.

DOI:10.1049/ip-h-2.1993.0022

出版商:IEE    

年代:1993

数据来源: IET