Abstract: A built-in antenna applied to sending and reception of radio waves of a few giga cycles is improved and made smaller, and is made suitable for industrial production and has its tuning bandwidth widened. “An antenna pattern (6) which resonates at &lgr;/4” is formed on a substrate (5) and a zigzag portion (6a) is provided on a portion of the antenna pattern (6) which resonates at &lgr;/4. On the other hand, the substrate (5) and a bobbin (8) are supported by a metallic frame (7), and “a helical coil (9) which resonates at &lgr;/4” is wound and formed upon the bobbin (8). Capacitance (c) is provided between the antenna pattern (6) which resonates at &lgr;/4 and the helical coil (9) to electrically couple them.

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: 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 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: 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 heater wire terminals and a vehicle body, 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 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: A shortened mast antenna with a compensating circuit between the antenna and a receiver and used in a state shorter than the resonant state of the antenna. The compensating circuit includes an FM compensating circuit made up with passive elements and compensating FM broadcast signals and an AM compensating circuit equipped with active elements which convert a high impedance into a low impedance so that the AM compensating circuit compensates AM broadcast signals. The attachment part of the antenna, to which the compensating circuit is directly connected, has a stray capacitance of 10 PF or less.

Abstract: A flat-plane antenna for mobile communications, used in automobiles, etc. including a table form antenna element made up of a conductive flat-plate section and a plurality of leg sections which connect to the flat-plate section to a ground plate, a strip line resonator provided beneath the table form antenna with a space in between, and a capacitor electrode provided on the strip line resonator directly under the center of the table form antenna element. A feeding line is connected to the strip line resonator.

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 a defogging heater wire is installed between the terminals and a vehicle body; alternately, FM choke coils can be installed which prevents the heater wire from receiving high-frequency signals from a power source of the heater wire. The heater wire which resonates in the FM frequency band but not in the AM frequency band is inductively and capacitively coupled to the 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: A compensating/amplifying device for a window glass antenna for an automobile. The device utilizes heating wires, which remove fog formed on the automobile window glass, as an antenna and includes band-pass filter coils interposed between a battery of the automobile and the heating wires, and the band-pass filter coils and a floating capacity between the heating wires and ground are used as a part of an input band-pass filter of a compensating amplifier.

Abstract: An automobile mast antenna used in a state shorter than its resonant state including an FM compensating circuit made only of passive elements and compensating for FM signals and an AM compensating circuit made of active elements that convert high impedance into low impedance and compensating for AM signals. The FM compensating circuit is formed with a primary resonance circuit and a secondary resonance circuit, in which the primary resonance circuit resonates in FM band via impedance of an antenna mast and loading coil which is attached to the antenna mast, and the secondary resonance circuit resonates in FM band via a coil and capacitor. The primary and secondary resonance circuits are coupled by electrostatic capacitance of attachment section of the antenna mast so as to form a double-tuned circuit.

Abstract: A motor-driven antenna including a logic circuit for stopping a motor which drives a rod antenna to be extended and retracted. The logic circuit is activated when a voltage corresponding to an electric current of the antenna motor reaches a predetermined level.

Abstract: A glass mounted antenna for car radio including an antenna element having a length that is in a resonant or non-resonant state with respect to FM frequencies, resonance circuits made up with spiral coils and capacitors so as to resonate in the FM band, a band-pass filter that passes only FM signals and no AM signals, and an AM impedance converter having an active element converting high-impedance signals into low impedance signals.

Abstract: A control device which raises and lowers a motorized automobile antenna by means of an antenna up-down switch, the power supply for a motor which drives the antenna being cut off when the antenna has reached its highest or lowest point and such a position of the antenna is detected. By supplying a voltage from the automobile ignition key to a control circuit when the antenna up-down switch is in a neutral position, the antenna is operated by the antenna up-down switch only when the automobile ignition key is on, and when the automobile ignition key is switched off, the antenna is retracted by a trigger which is actuated when the input of the control circuit reaches zero.

Abstract: A flat-plate antenna for use in mobile communications including a ground plate, a table-shape frame made up with a conductive top plate and connecting members which electrically connect the top plate to the ground plate, a capacitor electrode installed between the top plate and ground plate so as to resonate the table shape frame, and a strip line resonator installed under the table shape frame and is provided with a capacitor electrode for resonating the strip line resonator, the capacitor electrode being positioned beneath the central area of the top plate.

Abstract: A motor-driven automobile antenna equipped with a timer which stops a motor for extending and retracting a rod antenna via a rack rope after a lapse of time which is longer than the period of time required by the antenna to be fully extended or retracted.

Abstract: In a motorized automobile antenna control device for an antenna system wherein an antenna is raised when power supply of a radio receiver is switched on and lowered when the power supply is switched off, the antenna is prevented from being lowered for a predetermined period of time, for example two to ten seconds, after the power supply of the radio receiver is turned off by a timer so that unnecessary raising and lowering motions of the antenna are prevented when an ignition switch of an automobile is turned on.

Abstract: A non-grounded type ultrahigh frequency antenna including an antenna element having a length of .lambda./2 at a working frequency, a casing provided at the base of the antenna element, a metal section of the casing having a length of approximately .lambda./4 at the working frequency, and a metal plate provided in the casing and parallel to the metal section, one end of the metal plate being connected to the metal section and other end to the antenna element. The antanna is made parallel-resonant within a working frequency band by an electrostatic capacitance created between the metal plate and metal section and an inductance of the metal plate. The antenna element can be made slightly shorter than a length .lambda./2 at the working frequency and another metal plate can be provided between the antenna element and the metal plate so that a constant K-filter is formed by an electrostatic capacitance created by the another metal plate and the metal plate and a residual inductance of the antenna element.

Abstract: An automobile antenna including a high frequency signal processing unit provided near an antenna where the processing unit only tunes in a designated frequency band and amplifies it and further detects the amplified signal. The high frequency signal processing unit also adjusts the tuned frequency band at the high frequency signal processing unit based upon a tracking signal sent from an automobile receiver. Since the high frequency signal processing unit is provided adjacent to antennas, that is, near a glass antenna or mounted on an antenna mast, a loss which occur between the antenna and the receiver can be fully compensated for and noise interference can be avoided.

Abstract: A controlling device for an automobile motor driven antenna including a motor for extending and retracting an antenna by the power from a battery, and a control circuit for controlling the power. The control circuit includes a current detector for detecting the power flowing into and out of the motor and a current breaker which breaks the current when it is over a predesignated level so that a pair of relay contacts in the circuit changes the direction of the current so that the motor may make a forward or reverse rotation for extending or retracting the antenna and automatically make a stop of such rotation.

Abstract: A compensating amplifier for an automobile antenna which is relatively short and free from interference from high frequency band television signals. The amplifier includes an inductive element in a primary serial tuning circuit of a multiple tuning circuit of an antenna which is connected in parallel to a condenser, and the parallel resonant frequency of a parallel circuit which is formed by the inductive element and the condenser is set at approximately the same resonant frequency as the resonant frequency of the antenna.