Abstract: An antenna for radio communications such as portable telephone systems including a rod-form antenna element installed in the case of a radio communication set so that the antenna element can be retracted and pulled out with one portion of the antenna element remains outside of the case when the antenna element is accommodated inside the case; an impedance matching device connected to the feeding point of the antenna element and to the radio communication set; a stub which is a grounded conductive member and is installed so as to surround the outer circumference of the antenna element without touching the antenna element when the antenna element is accommodated inside the case. The base end of the antenna element and the base end of the stub are electrically coupled when the antenna element is completely accommodated inside the case so that good impedance matching can be obtained even when the antenna element is accommodated inside the case and that incoming calls are received without any failure.

Abstract: A diversity antenna for radio communications including a pair of conductive thin-film patterns used for a first antenna and another pair of conductive thin-film patterns used for a second antenna, the thin-film patterns being installed on a printed circuit board along the direction of the length of the circuit board; a first choke coil which is used to stop a leakage current from the first antenna and cause attenuation of a coupling current from the second antenna, the first choke coil being installed at a location where the leakage current distribution of the first antenna reaches the maximum in a feeder cable connected to the first antenna; and a second choke coil which is used to stop the leakage current from the second antenna, the second choke coil being installed at a location where the leakage current distribution of the second antenna reaches the maximum in a feeder cable for the second antenna.

Abstract: A retractable broad-band antenna for a portable telephone which includes a first antenna element which resonates in the lower region of the frequency band, a second antenna element which is coupled in series to the first antenna element via electrostatic capacitance and resonates in the higher region, and a call-receiving third antenna element mounted to the tip end of the second antenna element. The first and second antenna elements are shortened antenna elements in a form of helical coils. The first antenna element has an electrical length of .lambda.L/8 and is a non-grounded type having broad band characteristics by means of a matching device; and the second element has an electrical length of .lambda.H/2 wherein .lambda.H and .lambda.L are respectively the wave lengths at a center frequency of the higher and lower region of the frequency band used.

Abstract: A multi-stage telescopic antenna for use in vehicles and a method for manufacturing such an antenna in which the antenna element, which comprises uppermost rod and conductive pipes, is free of any bending or breaking damage even if a large load is applied to the antenna element from a lateral direction, and there is no permanent deformation occurs even after the load is removed, so that the antenna element can always be maintained straight and smooth and stable extension and retraction can be executed.At least the conductive pipes 12 through 14 are formed from a high-elasticity material obtained by heat-treating SUS 631. In the heat treatment, the material is heated at a standard temperature of 480.degree. C..+-.5.degree. C. and then gradually cooled.

Abstract: An automobile antenna including a defogging heater wire and a conductor combined into a simple structure for a good FM reception. FM choke coils, which prevents high-frequency signals from being transmitted from power supply circuit to the heater wire, is installed between the heater wire terminal and the power supply circuit for the heater wire, and the heater wire which resonates in the FM frequency band but not in the AM frequency band is inductively coupled to the conductor which is installed on the surface of the window glass and can resonate in the FM frequency band but not in the AM frequency band. The heater wire and conductor are installed in such a positional relationship as to create a double resonance.

Abstract: A driving apparatus for a motor-driven telescopic antenna including a rotary force transmitting mechanism installed between a drive side component rotated by a motor and a driven side component that extends and retracts an antenna element when rotated. The rotary force transmitting mechanism includes two coil springs provided circumferentially on the drive side component and two ridges formed with a space in between on the driven side component circumferentially so that when the drive and driven side components are rotated the ridges pushes the two springs to make compression deformations successively.

Abstract: A telecommunication system antenna including: a non-resonating three-wire type folded element which generates an unbalanced mode current and has a matching function; a sleeve element which consists of a conductive sleeve with its one end near the non-resonating three-wire type folded element and a conductive disk in a flange shape around the circumference of the other end of the conductive sleeve, so that the sleeve element radiates electromagnetic waves based on the unbalanced mode current generated by the non-resonating three-wire type folded element; and a coaxial line with its tip end inserted into the conductive sleeve of the sleeve element from the other end of the conductive sleeve so that the coaxial line is electrically connected to the conductive sleeve and to the non-resonating three-wire type folded element.

Abstract: An automobile antenna including a defogging heater wire and a conductor combined into a simple structure to accomplish a good FM reception. An FM choke coil which insulates in view of high-frequency the heater wire from the power supply circuit is installed between the heater wire terminal and the power supply circuit for the heater wire, and the heater wire which resonates in FM frequency band but not in AM frequency band is capacitively coupled to a conductor which is installed on the surface of the window glass and resonates in the FM frequency band but not in the AM frequency band. The heater wire and conductor are installed in such a positional relationship that a double resonance is created.

Abstract: An antenna mount 31 consisting of a hollow bulging member is formed so as protrude locally from the top of a portable telephone housing 30. A first antenna 10 with an electrical length of .lambda./4 is provided inside the antenna mount so that the base end Q of the first antenna is connected to a feeder cable 15. A second antenna 20 with an electrical length of 3 .lambda./4 is installed parallel to the first antenna 10 at a prescribed distance from the first antenna so that the second antenna can be freely extended from and retracted into the housing 30 via the antenna mount 31 and so that the base end 23 of the second antenna 20 is connected to the earthing means 32 of the housing 30 when the second antenna is extended from the housing 30, thus providing a J-form antenna formed by the first and second antennas 10 and 20. It is desirable that the first and second antennas 10 and 20 each be equipped with an element-shortening means.

Abstract: A control device for an electrically driven telescopic antenna including: a counting signal extracting circuit which detects the altered waveform of an rectified current generated during the forward or reverse rotation of a DC motor so as to extract counting signals; a command device which sends a control stop command to a motor drive control circuit when the counted value of the extracted counting signals reaches a certain preset value; a motor current monitoring circuit which monitors the current flow to the motor and outputs information on the completion of the antenna element extension/retraction action when the motor current value exceeds a prescribed value; and a correction device which corrects the counted value based upon the information outputted by the motor current monitoring circuit. The control device can include a large-capacitance capacitor for absorbing power supply fluctuations.

Abstract: A two-wave antenna for telephones used in vehicles which includes two radiating elements in which one end of each of the two radiating elements is respectively connected to one end of a single phase coil and the effective radiating lengths of the two radiating elements are respectively 1/2 .lambda..sub.1 to 5/8 .lambda..sub.1 and an electrical length of the phase coil is 3/2 .lambda..sub.1 to 5/4 .lambda..sub.1 so that currents of the same phase and two frequency bands are carried in the two radiating elements and wherein .lambda..sub.1 is the wavelength of the first band.

Abstract: An M-type car antenna for traffic information communication systems including an antenna element having a length which is one-half of the wavelength of the radio way used in the information communication systems, and a connector which is connected via an electrostatic coupling to the center-of the antenna element, the impedance matching and feeding being carried out by the connector. In this antenna, the voltage polarity of the connector at the coupling point and that of the center of the antenna element are set to be opposite from each other, and the electric current in the antenna element and that in the connector are set to be in the same direction. Thus, the M-type antenna is compact and easy to manufacture with stable antenna characteristics.

Abstract: An automobile loop antenna including a conductive loop and a coaxial cable. One end of the loop is connected to a core conductor of the coaxial cable, and the other end of the loop is connected to an outer conductor of the coaxial cable with a low-capacitance capacitor in between. A part of the outer conductor of the coaxial cable is connected to a metal part of an automobile so that the end of the coaxial cable is spaced 5 to 50 cm from the metal part.

Abstract: A device for controlling the angle of an optical axis of a headlamp which is advantageous in which the device is compact, light-weight and relatively inexpensive to manufacture and in which accurate optical axis angle control that corresponds to the operation of the operation switch can be achieved at all times regardless of the number of optical axis angle controllers used.The device comprises: an operation switch which includes a potentiometer for setting a control voltage, a motor which variably controls the angle of the optical axis of the headlamp based upon the control voltage generated by the operation switch, an optical axis angle voltage generator that includes a potentiometer for generating an optical axis angle voltage of the headlamp which is variably controlled by the motor, and a comparative controller which compares the optical axis angle voltage with the control voltage and then causes the motor to rotate in a direction in which the difference between the two voltages disappears.

Abstract: An electric extensible car antenna including an antenna element support cylinder detachably mounted to a cylindrical support member of an antenna attachment base from the outside of a car body; a single small-diameter rod antenna element inserted in an antenna element insertion hole of the support cylinder so as to be in contact with a conductive contact element; the proximal part of the antenna element led toward the proximal end of the support cylinder being guided in a direction by an antenna element guiding tube; and an antenna element extended and retracted by a rack-equipped flexible rope connected to the antenna element via an electric mechanism. It is desirable that the antenna element be made of an ultra-flexible material and that the support cylinder is made of a plurality of separate cylindrical units.

Abstract: An automobile antenna including a defogging heater wire and a conductor combined into a simple structure to accomplish a good FM reception. A capacitor which effects high-frequency grounding of the terminals of the defogging heater wire is installed between the terminals and a vehicle body. The heater wire which resonates in the FM frequency band but not in the AM frequency band is capacitively coupled to the conductor which resonates in the FM frequency band but not in the AM frequency band. The heater wire and the conductor are installed in such a positional relationship that a double resonance is created.

Abstract: [Object] To provide a method of manufacturing a helical antenna for satellite communications which has no local bent, etc. in the completed helical coil even though the conductor wire used is of an extremely pliable material, so that a high-quality helical antenna for use in satellite communications is obtained.[Structure] A winding frame 10 in which supporting elements 12 are projected in the form of a cross from the outer circumferential surface of a rod-form base 11 is first obtained. Wedge members 71 through 74, each of which having a configuration of a cylindrical body divided into four sections along its axis, are installed between the supporting elements 12. Then, with the cylindrical surfaces of the wedge members 71 through 74 being used as a winding guide, a conductor wire is wound in helical form through conductor wire installation grooves 13 formed on the edges of the supporting elements 12. Thus, a helical coil 20 is formed.