Koninklijke Philips Corporation N.v.

Nxp B.v.

Pxp B.v.

Kam Choon Kwong

Yeow Teng Toh

Hendricus Martinus Van Der Wijst

Alan Chin Leong Yeo

Mieu Ngan Pang

Hwee Bun Tan

Siow Ling Teo

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

Receivers () comprising television and radio inputs () for receiving television and radio signals and comprising switching circuits () with two first switches () to be activated in a first mode and located parallelly to the television input () and with two second switches () to be activated in a second mode and located anti-serially to the radio input (), and control circuits () for controlling the switching circuits () are modified in such a way that strong radio signals can no longer disturb the television signals. Thereby one of the first switches () and one of the second switches () together isolate the inputs () from each other, and the control circuit () supplies a first control signal to the first switches () and supplies a second control signal to non-common points of the anti-serial second switches (). This kind of receivers () no longer need different switching circuits () for shielded radio inputs and unshielded radio inputs. The switches () are diodes, and the control circuit () comprises transistors () for controlling the diodes.

Television receiver with isolated inputs

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 multimode front stage amplifier and method of amplifying a signal having an optimum signal output for weak signals as well as for strong signals provided for TV tuners. A product having a multimode front stage amplifier and provisions for selecting different modes of processing the signal.

Front stage amplifier with different modes

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.).

Power supply ripple rejection in tuner oscillator stage

In a method of automatic gain control for both TV and FM radio signals, the TV and FM radio signals are controllably amplified (AGC-AMP) to obtain amplifier output signals, the amplifier output signals are tuner processed (F, MIX, IF-AMP) to obtain tuner output signals, the tuner output signals are applied as control signals (T-AGC) to the controllable amplifier (AGC-AMP), a bandwidth of a thus formed AGC loop being wide enough for a TV channel, and the tuner output signals are narrow-band filtered (CF) to obtain narrow-band filtered signals having a bandwidth substantially corresponding to a bandwidth of an FM radio channel.

Growing community of inventors

Singapore, Singapore

Kam Choon Kwong