Appeal No. 1999-0859
Application No. 08/330,972
frequency bands, characterised in that the circuit
arrangement comprises:
- a mixer attenuating the image frequency comprising means
to phase-shift a received radio frequency signal, means
to mix said phase-shifted received radio signal and a
local oscillator signal, and means to phase-shift an
intermediate frequency signal resulting from the
mixing of said phase-shifted received radio signal and
said local oscillator signal, said mixer having at
least a first output and a second output with an
intermediate frequency corresponding to the first
frequency band being obtained from the first output of
the mixer, and an intermediate frequency corresponding
to the second frequency band being obtained from the
second output;
- a first bandpass filter, having a passsband [sic.
passband] with a width that substantially corresponds to the
bandwidth of the channels of the first frequency band, coupled
to said first output of said mixer;
- a second bandpass filter, having a passsband [sic.
passband] with a width that differs from said first bandpass
filter and susbstantially corresponds to the bandwidth of the
channels of the second frequency band, coupled to said second
output of said mixer; and
- a switch for selecting a desired intermediate frequency
corresponding to the desired frequency band either from the
output of said first bandpass filter or the output of said
second bandpass filter.
The Examiner relies on the following prior art:
Perlich 4,207,532 Jun. 10,
1980
Gorrie et al. (Gorrie) 5,214,796 May 25,
1993
Oto 5,437,051 Jul. 25,
1995
(filed Sep. 18, 1992)
3
Page: Previous 1 2 3 4 5 6 7 8 9 10 11 Next
Last modified: November 3, 2007