Telecommunications – Transmitter and receiver at same station – Radiotelephone equipment detail
Reexamination Certificate
1998-04-15
2001-04-03
Nguyen, Lee (Department: 2683)
Telecommunications
Transmitter and receiver at same station
Radiotelephone equipment detail
C455S090300, C455S097000, C455S575100, C343S702000, C343S895000, C379S433020, C379S428030
Reexamination Certificate
active
06212400
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention generally relates to an antenna device. More specifically, the present invention relates to an antenna device particularly for mobile radio telephone devices. The present invention is further directed to a mobile radio telephone device.
It is standard in mobile radio telephone devices to employ what are referred to as tuned or matched antennas, i.e. antennas whose effective length has a specific relationship to the wavelength &lgr; of the frequency range to be received. Given a mobile radio telephone device for what is referred to as the GSM standard, the frequency range to be received/transmitted amounts to approximately 900 MHZ through 1000 MHZ. Accordingly, the wavelength of this frequency range lies at approximately thirty through thirty-five cm.
An antenna that is tuned to half the wavelength of the frequency range to be received must thus exhibit an effective electrical length of about fifteen through eighteen cm for the GSM standard. It is obvious that an antenna having a length of 15-18 cm is a great disadvantage given the desire to make a mobile radio telephone device as handy as possible. A firmly attached antenna of this size projecting from the housing of the mobile radio telephone device is also out of the question for the reason that such an antenna is an extreme risk in view of damage by bending or breaking.
Up to now, it has been standard to provide a mobile radio telephone device with a rod antenna of the aforementioned length that can be telescoped in or to provide a helix antenna (spiral antenna) having the same electrical length or to provide a combination of helix and rod antenna. Before the mobile radio telephone device is placed in operation, the antenna must be pulled out in the case of a rod antenna. This solution has the disadvantage that the transmission/reception power of the mobile radio telephone device is deteriorated when the operator forgets to pull the antenna out before operation of the mobile radio telephone device. A helix antenna by itself has the disadvantage of poor reception/transmission properties, i.e. poor performance.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to create an antenna device that enables good transmission/reception properties of the antenna with little space requirement, even in the retracted condition.
This advantage is achieved by the combination of two known structuring principles. According to the present invention, an antenna device, particularly for mobile radio telephone devices, has a first helix antenna (spiral antenna), a second antenna connectible to the first helix antenna as well as an extensible rod antenna. The antenna device is thereby designed such that a connector element, for example a standard antenna contact element, connects only the rod antenna to the first helix antenna in the extended condition of the rod antenna. In the retracted condition of the rod antenna, by contrast, only the second helix antenna is connected to the first helix antenna by the connector element.
The solution of the present invention is thus composed of two individual antennas that can be fundamentally mounted independently of one another.
Advantageously, the first helix antenna, the second helix antenna as well as the rod antenna are respectively tuned to ¼ of the wavelength &lgr; of the frequency range to be transmitted/received. Each of the antennas thus forms what is referred to as a quarter-wave radiator (&lgr;/4 radiator) in and of itself. Due to the combination of the antennas of the present invention, a further quarter-wave radiator is respectively coupled to the first quarter-wave radiator, namely to the first helix antenna. In the extended condition of the rod antenna, the rod antenna is coupled as a quarter-wave radiator to the first helix antenna; in the retracted condition of the rod antenna, by contrast, the second helix antenna is coupled to the first helix antenna. Both in the retracted as well as in the extended condition of the rod antenna, a &lgr;/2 radiator is formed overall. This represents an advantage for tuning of the antenna device for the necessary reception/transmission power.
Advantageously, the region of the rod antenna that lies in the proximity of the helix antennas in the retracted condition of the rod antenna is composed of a non-conductive material. It is thereby assured that the fields of the first and of the second helix antenna are hardly influenced by the rod antenna in the retracted condition of the rod antenna wherein only the second helix antenna is coupled to the first helix antenna.
The first helix antenna is preferably a coil on a printed circuit board.
An especially low space requirement derives when the rod antenna is arranged coaxially relative to the helix antenna. In this respect, it is especially beneficial when the first helix antenna is arranged parallel to and slightly offset from the second helix antenna.
The present invention also provides a mobile radio telephone device with an antenna device of the aforementioned species. It is thereby especially advantageous in view of the space requirement when the second helix antenna is accommodated in a stub-shaped projection in the housing of the mobile radio telephone device.
Additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the presently preferred embodiments and from the drawings.
REFERENCES:
patent: 5504494 (1996-04-01), Chatzipetros et al.
patent: 5734351 (1998-03-01), Ojantakanen et al.
patent: 5907306 (1999-12-01), Karabinis et al.
patent: 5963871 (1999-10-01), Zhinong et al.
patent: 5999133 (1999-12-01), Svensson
Ferguson Keith
Nguyen Lee
Schiff & Hardin & Waite
Siemens Aktiengesellschaft
LandOfFree
Antenna device for mobile radio telephone devices does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Antenna device for mobile radio telephone devices, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Antenna device for mobile radio telephone devices will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2504587