Abstract: An electromagnetic field band-stop filter includes a plurality of unit structures that have reflection characteristics on an electromagnetic wave of a predetermined frequency. Each of the plurality of unit structures includes: a plurality of electrode parts each of which is disposed along a side of a polygon in a non-contact manner with another electrode part; and a plurality of conductor parts which are provided for the plurality of electrode parts on a one-to-one basis and each of which has at least one bent portion between one end and other end, the one ends of the plurality of conductor parts being connected to the electrode parts on a one-to-one basis and the other ends of the plurality of conductor parts being connected at one point on an inner side of the electrode parts in the individual unit structure.

Abstract: A frequency selective surface having a steep attenuation slope (high sharpness) characteristic is provided without decreasing the line width of a conductive pattern nor the pattern interval thereof. In a frequency selective surface having a structure in which resonators k1xy having identical shapes are periodically arrayed on a dielectric substrate 101, each resonator k1xy includes a cross-shaped conductive pattern formed on the dielectric substrate 101 and a lateral pattern 10 and a longitudinal pattern 20 forming a cross are shaped such that each pattern is extended by a predetermined length in respective directions, each pattern extended by the predetermined length is further extended in both directions orthogonal to each other on the dielectric substrate 101, and leading end parts of the respective further extensions face each other at a predetermined interval d.

Abstract: To provide a frequency selective surface of which an operating frequency and a bandwidth thereof can be readily adjusted.

Abstract: A radar apparatus includes: a transmission unit that transmits a chirp signal; a reception unit that receives a reflected signal that is the chirp signal reflected by a scatterer; and a pole calculation unit that calculates a beat signal based on the chirp signal and the reflected signal and calculates a pole of the beat signal by eigenvalue decomposition of an autocorrelation matrix of the beat signal. The radar apparatus further includes: a complex amplitude calculation unit that calculates a complex amplitude corresponding to the pole by using a least squares method between a basis waveform corresponding to the pole and the beat signal; a distance calculation unit that calculates a distance to the scatterer based on the beat signal; and an intensity calculation unit that calculates an intensity of the reflected signal based on the complex amplitude.

Abstract: To accurately estimate frequency characteristics from structural parameters of a frequency selective surface.

Abstract: A radar apparatus (1) of the present embodiment includes a transmitting unit (12) that transmits a frequency chirp signal whose frequency linearly changes with time, a receiving unit (13) that receives a reflected wave that is the frequency chirp signal reflected by an object, a mixer (14) that mixes the transmitted frequency chirp signal and the received reflected wave to obtain a beat signal, a frequency estimation unit (15) that estimates a frequency of the beat signal, and a distance estimation unit (16) that estimates a distance to the object based on the frequency of the beat signal. The frequency estimation unit (15) calculates an autoregressive coefficient of an autoregressive model from a sequence of discrete signal values of the beat signal and estimates the frequency of the beat signal using a base frequency that is based on a pole of the autoregressive model.

Abstract: To provide a frequency selective surface of which an operating frequency and a bandwidth thereof can be readily adjusted.

Abstract: To accurately estimate frequency characteristics from structural parameters of a frequency selective surface.

Abstract: A frequency selective surface having a steep attenuation slope (high sharpness) characteristic is provided without decreasing the line width of a conductive pattern nor the pattern interval thereof. In a frequency selective surface having a structure in which resonators k1xy having identical shapes are periodically arrayed on a dielectric substrate 101, each resonator k1xy includes a cross-shaped conductive pattern formed on the dielectric substrate 101 and a lateral pattern 10 and a longitudinal pattern 20 forming a cross are shaped such that each pattern is extended by a predetermined length in respective directions, each pattern extended by the predetermined length is further extended in both directions orthogonal to each other on the dielectric substrate 101, and leading end parts of the respective further extensions face each other at a predetermined interval d.

Abstract: An electromagnetic field band-stop filter includes a plurality of unit structures that have reflection characteristics on an electromagnetic wave of a predetermined frequency. Each of the plurality of unit structures includes: a plurality of electrode parts each of which is disposed along a side of a polygon in a non-contact manner with another electrode part; and a plurality of conductor parts which are provided for the plurality of electrode parts on a one-to-one basis and each of which has at least one bent portion between one end and other end, the one ends of the plurality of conductor parts being connected to the electrode parts on a one-to-one basis and the other ends of the plurality of conductor parts being connected at one point on an inner side of the electrode parts in the individual unit structure.