Authors had proposed a hybrid electromagnetic field analysis method suitable for an airport surface so far. In this paper, the hybrid method is validated by measurements by using a 1/50 scale-model of an airport considering several layouts of the buildings and sloping ground. The measured power distributions agreed with the analyzed ones within 5 dB errors excepting null points and the null positions of the distribution is also estimated within one wavelength errors.

A novel design technique for two-dimensional (2-D) waveguide slot arrays is proposed in this paper that combines a full-wave method of moments (MoM) analysis and an equivalent circuit with the explicit restraint of input matching. The admittance and slot spacing are determined first in an equivalent circuit to realize the desired distribution of power dissipation and phase, with the explicit restraint of input matching. Secondly by applying a full-wave MoM analysis to the finite 2-D array, slot parameters are iteratively determined to realize the active admittance designed above where slot mutual coupling and wall thickness are fully taken into account. The admittance, treated as the key parameter in the equivalent circuit corresponds to the power dissipation of the slots but not to the slot voltage, which is directly synthesized from the radiation pattern. The initial value of the power dissipation is assumed to be proportional to the square of the amplitude of the desired slot voltage. This assumption leads to a feedback procedure, because the resultant slot voltage distribution generally differs from the desired ones due to the effect of non-uniformity in the characteristic impedance on slot apertures. This slot voltage error is used to renew the initial distribution of power dissipation in the equivalent circuit. Generally, only one feedback cycle is needed. Two 2427-element arrays with uniform and Taylor distributions were designed and fabricated at 25.3 GHz. The measured overall reflections for both antennas were suppressed below -18 dB over the 24.3-26.3 GHz frequency range. High aperture efficiencies of 86.8% and 55.1% were realized for the antennas with uniform and Taylor distributions, the latter of which has very low sidelobes below -33 dB in both the E- and H-planes.

We propose a wave analysis method for probe-fed Radial Line Planar Antennas (RLPAs) which yields an approximate solution for the aperture field distribution and scattering by loaded probes. Damping of electric power in the radial line due to radiation by antenna elements is included. The method can accommodate the effect of all conductors, including the terminating wall, by introducing the concept of equivalent posts. We have found good correspondence between the measured and calculated values of the aperture field distribution. The proposed method is effective for general geometries of probe-fed RLPAs.

Aged people who live alone are in particular need of a daily health check, medication, and of warm communication with family and friends. The authors have been developing a life-support computer system with such functions. Among them, a daily health check function with the capability of measuring blood pressure, detecting diseases from coughing, and so on would in particular be very powerful for primary care. As a first step to achieving quick services for a daily health check with a personal computer, utilization of cough information is considered. Features of cough data are analyzed aiming at developing an automatic cough data detection method. This paper proposes a novel method for extracting cough signals from other types of signals. The differential coefficient of a low-pass filtered waveform is first shown to be an effective parameter for discriminating between vowel and cough signals, and the relationship between cut-off frequency and cough detection rate is clarified. This parameter is then applied to cough signals mixed with vowel signals or white noises to evaluate robustness. The evaluation tests show that the cough feature can be perfectly detected for a 20 dB S/N ratio when the cut-off frequency is set to 24 [Hz]. The experimental results suggest that the proposed cough detection method can be a useful tool as a primary care for aged people with a bronchitis like an asthmatic bronchitis and a bronchopneumonia.