Nxp B.v.

Koninklijke Philips Corporation N.v.

Pxp B.v.

Yeow Teng Toh

Kam Choon Kwong

Hendricus Martinus Van Der Wijst

Siow Ling Teo

Eng Nguen Pang

A receiver can handle different types of reception signals, such as, for example, TV and FM-radio signals. In the receiver, a mixer (MIX) mixes a reception signal with an oscillator signal (OOS) so as to obtain a mixer output signal (MOS), which comprises a frequency-shifted version of the reception signal. An intermediate frequency amplifier (IFAMP) applies an amplified mixer output signal (MOSA) to two different intermediate frequency filters: one for first type reception signals and another for second type reception signals. A switchable coupling section (DBTP, SWA) is coupled between the mixer (MIX) and the intermediate frequency amplifier (IFAMP). The switchable coupling section (DBTP, SWA) is switchable to a first state and a second state. In the first state, the mixer output signal (MOS) substantially reaches an input (IAD) of the intermediate frequency amplifier (IFAMP) via a first coupling path (DTBP). In the second state, the mixer output signal (MOS) substantially reaches the input (IAD) of the intermediate frequency amplifier (IFAMP) via a second coupling path (SWA).

Receiver for different types of reception signals

The present invention relates to a combination RF tuner capable of receiving signals from the FM radio band and from the TV band. Prior art combination tuners had to compromise in quality resulting in combination tuners that neither exhibited high-end FM nor TV-signal reception behavior. A combination RF tuner capable of optimal receiving an FM-radio signal type and a TV signal type, comprising a switch-able tuned input filter (), is proposed. One response of the input filter () provides a sufficient big bandwidth for enabling reception of the TV-signal type. The input filter () of the invention can be switched, providing a second response that has a smaller bandwidth for enabling reception of the FM-radio signal type. The second response can be realized by substantially bypassing an 10 inductive element () (e.g., comprising a inductor, L, in series with a damping resistor, R) of the input filter ().

Switch-able band-tracking input filter for combination tuner

A television tuner comprises a tunable bandpass filter () for selecting a desired input channel with an image canceling capacitor (C) for rejecting the image frequency of the desired input channel. In order to avoid the necessity of different printed circuit boards for NTSC-type television tuners and for PAL-type television tuners, the image canceling capacitor (C) is made of first () and second () traces of the printed circuit board while a third trace () is connected to the second trace () by a jumper () only in case of a PAL-type tuner.

Printed circuit board configurable television tuner

By using ICs with combined inputs for the VHF-high bandpass circuit and the UHF bandpass circuit, undesirable resonances occur which are caused by one of the tuned circuits. The problem is solved by providing a switching means for decoupling the UHF bandpass circuit from the combined inputs when a VHF-high band signal is received by the VHF-high bandpass circuit. The switching means comprises a switch coupled between the UHF bandpass circuit and the common inputs.

Switch in UHF bandpass

A bipolar transistor (Tr) in an oscillator stage of a tuner is provided with a diode (D) in series with a resistor (R) coupled between the base of the transistor (Tr) and the reference voltage to which the emitter of the transistor (Tr) is coupled. The diode (D) allows a decreased resistor (R) value which causes the supply voltage ripple (Vr) on the collector originating from the base to decrease so as to better compensate the supply ripple (Vr) on the collector directly originating from the supply voltage (Vs.).

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Singapore, Singapore

Yeow Teng Toh