The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 24, 1993
Filed:
Jan. 30, 1991
Horst Dorrie, Berlin, DE;
Uwe Militz, Berlin, DE;
Robert Bosch GmbH, Stuttgart, DE;
Abstract
To permit use of a hand-held transceiver, such as a radio telephone, as a vehicular car telephone, and operation thereof via a car radio receiving antenna (10), an active multi-range antenna switch is connected between the antenna (10), the car radio (27) and the transceiver (29). The antenna is connected to the car radio (27) through a first channel (13) which includes a low-pass filter (15) and an amplifier; the antenna (10) is further connected to the radio telephone via a second channel (14) which includes a high-pass filter (17), an inter-channel modulation suppression filter (18), an amplifier (19) connected to amplify signals from the radio telephone, and a power sensing relay (20) which, when the transceiver (29) is in receiving mode, bridges or shunts the amplifier (19), but opens the switch when the transceiver is in a transmitting mode, to provide amplification of transmission signals from the transceiver or radio telephone. The active switch can be connected to the car battery (32) which can also be connected through a separable connector (31, 30) to the radio telephone so that, when used in the vehicle, it will not draw on its own internal power supply (35), but be powered from the car radio. The low-pass filer (15) has a cut-off frequency of, approximately, 108 MHz and blocks transmission of the radio telephone signals in the car radio, the high-pass filter (17) having a low frequency cut-off for example of also 108 MHz, transmitting, however, readily within the 400 MHz band for portable telephones.