Abstract: To improve quality of a radome using a cyanate ester resin for a skin layer. A radome is formed of a multilayer structure in which a plurality of skin layers are layered on a surface of a core member. The plurality of skin layers include a first fiber reinforced plastic layer containing the cyanate ester resin and a fiber material and a second fiber reinforced plastic layer containing an epoxy resin and a fiber material. The second fiber reinforced plastic layer is disposed at a position in contact with the surface of the core member. A proportion of a thickness of the second fiber reinforced plastic layer to a thickness of all of the skin layers is preferably 50% or less.

Abstract: A method of molding a sandwich panel includes a step of providing, on one or both surfaces of an (a) core material, a prepreg or the prepreg and an adhesive as a (b) skin material. The (a) core material is a super engineering plastic foam having a glass transition temperature of greater than 200° C. The (b) skin material contains: a (b-1) epoxy resin having an average molecular weight of 1300 or more or having a trishydroxymethane-type or cresol novolac-type structure and containing, in a total epoxy resin, an amount of 70 to 100 mass % of an epoxy resin that is semi-solid or solid; a (b-2) epoxy resin containing, in the total epoxy resin, an amount of 0 to 30 mass % of an epoxy resin that is liquid; and a (b-3) curing agent.

Abstract: To improve quality of a radome using a cyanate ester resin for a skin layer. A radome is formed of a multilayer structure in which a plurality of skin layers are layered on a surface of a core member. The plurality of skin layers include a first fiber reinforced plastic layer containing the cyanate ester resin and a fiber material and a second fiber reinforced plastic layer containing an epoxy resin and a fiber material. The second fiber reinforced plastic layer is disposed at a position in contact with the surface of the core member. A proportion of a thickness of the second fiber reinforced plastic layer to a thickness of all of the skin layers is preferably 50% or less.

Abstract: A method of molding a sandwich panel includes a step of providing, on one or both surfaces of an (a) core material, a prepreg or the prepreg and an adhesive as a (b) skin material. The (a) core material is a super engineering plastic foam having a glass transition temperature of greater than 200° C. The (b) skin material contains: a (b-1) epoxy resin having an average molecular weight of 1300 or more or having a trishydroxymethane-type or cresol novolac-type structure and containing, in a total epoxy resin, an amount of 70 to 100 mass % of an epoxy resin that is semi-solid or solid; a (b-2) epoxy resin containing, in the total epoxy resin, an amount of 0 to 30 mass % of an epoxy resin that is liquid; and a (b-3) curing agent.

Abstract: An epoxy resin composition for a fiber-reinforced composite material includes: (a) one or more epoxy resins; (b) an aromatic diamine compound; (c) a dicyandiamide; (d) a urea compound; and (e) an amine adduct compound, blended in specific ranges.

Abstract: A cyanate ester resin composition contains: a cyanate ester resin; a curing agent or a curing accelerator; silica microparticles; and core-shell rubber particles; in which the resin composition includes from 1 to 5 parts by mass of the silica microparticles and from 2 to 10 parts by mass of the core-shell rubber particles based on 100 parts by mass of the cyanate ester resin, and a mass ratio of the silica microparticles to the core-shell rubber particles is from 1/1 to 1/5.

Abstract: A cyanate ester resin composition contains: a cyanate ester resin; a curing agent or a curing accelerator; silica microparticles; and core-shell rubber particles; in which the resin composition includes from 1 to 5 parts by mass of the silica microparticles and from 2 to 10 parts by mass of the core-shell rubber particles based on 100 parts by mass of the cyanate ester resin, and a mass ratio of the silica microparticles to the core-shell rubber particles is from 1/1 to 1/5.

Abstract: The transponder unit provided in a DME ground apparatus detects the transmission rate at which to transmit the pulse-pairs constituting a response signal. The threshold of the reception level of the pulse detection unit provided in the transponder unit is raised as the transmission rate increases.

Abstract: A transponder unit of a DME ground apparatus receives an interrogation signal and converts the same to an IF signal. The unit performs analog-to-digital conversion on the IF signal, generating a digital interrogation signal. The unit calculates two detected outputs whose frequencies are ±900 kHz deviated with respect to the center frequency of the digital interrogation signal. Then, the transponder unit compares the two detected outputs and the digital interrogation signal in terms of magnitude, thereby to determine whether a response signal should be transmitted.

Abstract: In a DME ground apparatus, under the control of a transmission-rate monitoring control unit, the transponder unit decodes an interrogation signal it has received and generates a response signal. The transmission rate at which to transmit the response signal is monitored. If the result of the monitoring indicates that the transmission rate has reached a preset value, the response signal is transmitted from the DME ground apparatus. If the result of the monitoring indicates that the transmission rate has not reached a preset value, squitter pulses are transmitted from the DME ground apparatus.

Abstract: A transmitting apparatus comprises a generator for generating a pulse signal having a waveform approximated to the Gaussian error function at a prescribed timing, a transmitter for power-amplifying a pulse signal generated by the generator, and transmitting the amplified pulse signal, an evaluator for extracting a pulse waveform part from the power-amplified pulse signal, comparing the extracted pulse waveform part with an ideal waveform so as to obtain an error amount between the pulse waveform part and the ideal waveform, and evaluating whether or not the error amount is within a prescribed error range, and a controller for causing the generator to subject the waveform of the pulse signal to correction in such a manner that the error amount becomes smaller each time an evaluation result of the evaluator is that the error amount is out of the prescribed error range.

Abstract: A transponder unit of a DME ground apparatus receives an interrogation signal and converts the same to an IF signal. The unit performs analog-to-digital conversion on the IF signal, generating a digital interrogation signal. The unit calculates two detected outputs whose frequencies are ±900 kHz deviated with respect to the center frequency of the digital interrogation signal. Then, the transponder unit compares the two detected outputs and the digital interrogation signal in terms of magnitude, thereby to determine whether a response signal should be transmitted.

Abstract: In a DME ground apparatus, under the control of a transmission-rate monitoring control unit, the transponder unit decodes an interrogation signal it has received and generates a response signal. The transmission rate at which to transmit the response signal is monitored. If the result of the monitoring indicates that the transmission rate has reached a preset value, the response signal is transmitted from the DME ground apparatus. If the result of the monitoring indicates that the transmission rate has not reached a preset value, squitter pulses are transmitted from the DME ground apparatus.

Abstract: The transponder unit provided in a DME ground apparatus detects the transmission rate at which to transmit the pulse-pairs constituting a response signal. The threshold of the reception level of the pulse detection unit provided in the transponder unit is raised as the transmission rate increases.

Abstract: A transmitting apparatus comprises a generator for generating a pulse signal having a waveform approximated to the Gaussian error function at a prescribed timing, a transmitter for power-amplifying a pulse signal generated by the generator, and transmitting the amplified pulse signal, an evaluator for extracting a pulse waveform part from the power-amplified pulse signal, comparing the extracted pulse waveform part with an ideal waveform so as to obtain an error amount between the pulse waveform part and the ideal waveform, and evaluating whether or not the error amount is within a prescribed error range, and a controller for causing the generator to subject the waveform of the pulse signal to correction in such a manner that the error amount becomes smaller each time an evaluation result of the evaluator is that the error amount is out of the prescribed error range.