Abstract: A signal processing device includes: a processor; and a memory having instructions. When executed by the processor, the instructions cause the signal processing device to perform operations including: converting a first signal that is a time domain signal into a second signal that is a frequency domain signal in response to reception of the first signal, the first signal containing noise superimposed on a broadcast electric signal derived from a broadcast electromagnetic wave, the noise having peaks of amplitude at regular frequency intervals in the frequency domain; calculating a frequency interval between the peaks of the noise in the frequency domain based on a correlation of the second signal; determining a frequency shift amount in the frequency domain based on the frequency interval; and shifting a frequency of the second signal by the frequency shift amount to create a frequency-shifted signal.

Abstract: A signal processing device includes: a processor; and a memory having instructions. When executed by the processor, the instructions cause the signal processing device to perform operations including: converting a first signal that is a time domain signal into a second signal that is a frequency domain signal in response to reception of the first signal, the first signal containing noise superimposed on a broadcast electric signal derived from a broadcast electromagnetic wave, the noise having peaks of amplitude at regular frequency intervals in the frequency domain; calculating a frequency interval between the peaks of the noise in the frequency domain based on a correlation of the second signal; determining a frequency shift amount in the frequency domain based on the frequency interval; and shifting a frequency of the second signal by the frequency shift amount to create a frequency-shifted signal.

Abstract: A receiving device includes: a frequency mixer that converts a frequency of a reception signal to a baseband; an envelope demodulator; an upper sideband demodulator; and a lower sideband demodulator. Each of the envelope demodulator, the upper sideband demodulator and the lower sideband demodulator demodulates an output from the frequency mixer. The receiving device further includes: a first adder that adds an output from the envelope demodulator and an inverted output obtained by inverting an output from the upper sideband demodulator; a second adder that adds the output from the envelope demodulator and an inverted output obtained by inverting an output from the lower sideband demodulator; and a third adder that adds the output from the envelope demodulator, an inverted output obtained by inverting an output from the first adder, and an inverted output obtained by inverting an output from the second adder, to output a demodulation signal.

Abstract: A receiving device includes: a frequency mixer that converts a frequency of a reception signal to a baseband; an envelope demodulator; an upper sideband demodulator; and a lower sideband demodulator. Each of the envelope demodulator, the upper sideband demodulator and the lower sideband demodulator demodulates an output from the frequency mixer. The receiving device further includes: a first adder that adds an output from the envelope demodulator and an inverted output obtained by inverting an output from the upper sideband demodulator; a second adder that adds the output from the envelope demodulator and an inverted output obtained by inverting an output from the lower sideband demodulator; and a third adder that adds the output from the envelope demodulator, an inverted output obtained by inverting an output from the first adder, and an inverted output obtained by inverting an output from the second adder, to output a demodulation signal.

Abstract: A C/N ratio detection circuit includes a voltage detector, an averaging section, a time variation range calculator, and a C/N ratio calculator. The voltage detector measures an input voltage of a signal. The averaging section calculates an average of the input voltage over a predetermined time. The time variation range calculator calculates a time variation range of the input voltage over the predetermined time. The C/N ratio calculator calculates a C/N ratio of the signal by using the average and time variation range of the input voltage.

Abstract: A C/N ratio detection circuit includes a voltage detector, an averaging section, a time variation range calculator, and a C/N ratio calculator. The voltage detector measures an input voltage of a signal. The averaging section calculates an average of the input voltage over a predetermined time. The time variation range calculator calculates a time variation range of the input voltage over the predetermined time. The C/N ratio calculator calculates a C/N ratio of the signal by using the average and time variation range of the input voltage.

Abstract: A photonic crystal device according to the present invention includes: a first dielectric substrate 104 having a first lattice structure, of which the dielectric constant changes periodically within a first plane; a second dielectric substrate 105 having a second lattice structure, of which the dielectric constant changes periodically within a second plane; and an adjustment device (pivot 303) for changing a photonic band structure, defined by the first and second lattice structures, by varying relative arrangement of the first and second lattice structures. The first and second dielectric substrates 104 and 105 are stacked one upon the other.

Abstract: A slot antenna apparatus includes a grounding conductor having an outer edge including a first portion and a second portion, a one-end-opened slot formed in the grounding conductor along a radiation direction such that an open end is provided at a center of the first portion, a first feed line intersecting with the slot to feed radio-frequency signals, a second feed line connected to an external circuit, and a signal processing circuit including active elements and connected between the first and second feed lines and connected to the grounding conductor. The grounding conductor is configured to be symmetric about an axis parallel to the radiation direction and passing through the slot, and is provided with a grounding terminal on the axis of symmetry at the second portion. The grounding terminal is to be connected to a ground of the external circuit.

Abstract: A slot antenna apparatus includes a grounding conductor having an outer edge including a first portion facing a radiation direction and a second portion other than the first portion, a one-end-open feed slot formed in the grounding conductor along the radiation direction such that an open end is provided at a center of the first portion, and a feed line including a strip conductor close to the grounding conductor and intersecting with the feed slot at at least a part thereof to feed a radio frequency signal to the feed slot. The slot antenna apparatus further comprises at least one one-end-open parasitic slot having an electrical length equivalent to one-quarter effective wavelength in a certain stop band, the parasitic slot having an open end at the second portion, and being formed in the grounding conductor so as not to intersect with the feed line.

Abstract: A slot antenna apparatus including: a grounding conductor having an outer edge including a first portion facing a radiation direction and a second portion other than the first portion, a one-end-open slot formed in the grounding conductor along the radiation direction such that an open end is provided at a center of the first portion, and a feed line including a strip conductor close to the grounding conductor and intersecting with the slot at least a part thereof to feed a radio frequency signal to the slot. The grounding conductor is formed to include at least one section at the second portion, the at least one section gradually approaches an axis passing through the slot and parallel to the radiation direction with increasing distance from the first portion.

Abstract: A photonic crystal device according to the present invention includes: a first dielectric substrate 104 having a first lattice structure, of which the dielectric constant changes periodically within a first plane; a second dielectric substrate 105 having a second lattice structure, of which the dielectric constant changes periodically within a second plane; and an adjustment device (pivot 303) for changing a photonic band structure, defined by the first and second lattice structures, by varying relative arrangement of the first and second lattice structures. The first and second dielectric substrates 104 and 105 are stacked one upon the other.

Abstract: A photonic crystal device according to the present invention includes: a first dielectric substrate 104 having a first lattice structure, of which the dielectric constant changes periodically within a first plane; a second dielectric substrate 105 having a second lattice structure, of which the dielectric constant changes periodically within a second plane; and an adjustment device (pivot 303) for changing a photonic band structure, defined by the first and second lattice structures, by varying relative arrangement of the first and second lattice structures. The first and second dielectric substrates 104 and 105 are stacked one upon the other.

Abstract: A polarization switching/variable directivity antenna according to the present invention includes a ground conductor plate 12 on a surface of a dielectric substrate 11, and has a radiation element 13, a directivity switching element 15, and polarization switching elements 16 provided on the ground conductor plate 12 side of the dielectric substrate 11. The radiation element 13 includes a first slot 17a formed by removing a loop-like portion from the ground conductor plate 12. The directivity switching element 15 includes a second slot 17b formed by removing a loop-like portion from the ground conductor plate 12 and directivity switching switches 18. The polarization switching elements 16 includes a third slot 17c formed by removing a linear-shaped portion from the ground conductor plate 12 and polarization switching switches 19a to 19d. Through control of the directivity switching switches 18, switching of a maximum gain direction of radiation directivity of the antenna is realized.

Abstract: A variable slot antenna includes: ground conductors 101a and 101b, which are divided by a slot region 109 both of whose both ends are open ends 111a and 111b; a feed line 115 for feeding power to the slot region 109; a first selective conduction path 119 connecting between the ground conductors 101a and 101b in a direction of the open end 111a as viewed from a feeding site 113; and a second selective conduction path 121 connecting between the ground conductors 101a and 101b in a direction of the open end 111b as viewed from the feeding site 113. In a first driving state, the first selective conduction path 119 is allowed to conduct and the second selective conduction path 121 is left open, so that a main beam is emitted in a direction 123a of the second selective conduction path 121 as viewed from the feeding site 113. In another driving state, the selective conduction paths are controlled differently so that the main beam direction is switched to a direction 123b.

Abstract: A transmission line pair has two transmission lines placed adjacent to each other in parallel to a signal transmission direction of the transmission lines as a whole. Each of the transmission lines includes a first signal conductor which is placed on one surface of a substrate formed from a dielectric or semiconductor and which is formed so as to be curved toward a first rotational direction within the surface, and a second signal conductor which is formed so as to be curved toward a second rotational direction opposite to the first rotational direction and which is placed in the surface so as to be electrically connected in series to the first signal conductor. A transmission-direction reversal portion in which a signal is transmitted along a direction reversed with respect to the signal transmission direction of the transmission lines as a whole is formed so as to include at least part of the first signal conductor and part of the second signal conductor.

Abstract: A slot antenna apparatus includes a grounding conductor having an outer edge including a first portion and a second portion, a one-end-opened slot formed in the grounding conductor along a radiation direction such that an open end is provided at a center of the first portion, a first feed line intersecting with the slot to feed radio-frequency signals, a second feed line connected to an external circuit, and a signal processing circuit including active elements and connected between the first and second feed lines and connected to the grounding conductor. The grounding conductor is configured to be symmetric about an axis parallel to the radiation direction and passing through the slot, and is provided with a grounding terminal on the axis of symmetry at the second portion. The grounding terminal is to be connected to a ground of the external circuit.

Abstract: A differential transmission line includes: a substrate; a ground conductor layer; and a first and a second signal conductor disposed in parallel to each other on the substrate. The first signal conductor and the ground conductor layer compose a first transmission line, whereas the second signal conductor and the ground conductor layer compose a second transmission line. The first transmission line and the second transmission line compose a differential transmission line. The differential transmission line includes two straight regions and a curved region, interconnecting the two straight regions.

Abstract: A variable-directivity antenna according to the present invention includes at least three linear passive elements, which are arranged parallel to a Z-axis so as to surround a feed element. Each of those passive elements includes at least two element pieces, etc. that are arranged parallel to the Z-axis and switching elements, etc. of a first type. The passive element assembly further includes at least one switching element, etc. of a second type that makes two adjacent passive elements electrically continuous with each other when turned ON but electrically insulates them from each other when turned OFF. By turning ON and OFF the at least one switching element of the first type and the at least one switching element of the second type, the antenna can change its directivities.

Abstract: A polarization switching/variable directivity antenna according to the present invention includes a ground conductor plate 12 on a surface of a dielectric substrate 11, and has a radiation element 13, a directivity switching element 15, and polarization switching elements 16 provided on the ground conductor plate 12 side of the dielectric substrate 11. The radiation element 13 includes a first slot 17a formed by removing a loop-like portion from the ground conductor plate 12. The directivity switching element 15 includes a second slot 17b formed by removing a loop-like portion from the ground conductor plate 12 and directivity switching switches 18. The polarization switching elements 16 includes a third slot 17c formed by removing a linear-shaped portion from the ground conductor plate 12 and polarization switching switches 19a to 19d. Through control of the directivity switching switches 18, switching of a maximum gain direction of radiation directivity of the antenna is realized.

Abstract: A slot antenna apparatus including: a grounding conductor having an outer edge including a first portion facing a radiation direction and a second portion other than the first portion, a one-end-open slot formed in the grounding conductor along the radiation direction such that an open end is provided at a center of the first portion, and a feed line including a strip conductor close to the grounding conductor and intersecting with the slot at least a part thereof to feed a radio frequency signal to the slot. The grounding conductor is formed to include at least one section at the second portion, the at least one section gradually approaches an axis passing through the slot and parallel to the radiation direction with increasing distance from the first portion.