86results about "Automatic frequency band scanning" patented technology

It is determined, in accordance with a signal supplied by a tuner and indicating a signal reception state of the tuner, whether or not signal reception has been performed normally. Then, power supply to the tuner is stopped when it is determined that signal reception has not been performed normally. Further, it is detected whether or not an antenna has been connected to the tuner apparatus. Then, power supply to the tuner is stopped when it is determined that the antenna has not been connected to the tuner apparatus.

An apparatus and method for automatically tuning a resonant circuit in a chiroptical measurement system. A sample cell holds a sample being measured for a chiroptical property as the sample is modulated by the resonant circuit. A signal source coupled to the resonant circuit generates a driving signal at one of a plurality of frequencies to modulate the resonant circuit. The frequencies are within a range of expected resonant frequencies for the resonant circuit. A feedback loop circuit coupled to the signal source is used to adjust the frequency of the driving signal to another of the frequencies in response to a feedback signal associated with a measured parameter of the driving signal. In this way, the frequency of the driving signal is adjusted to create a resonant condition. The driving signal may also be applied at a reduced power level so that the resonant circuit can be driven at off-resonant frequencies within the range of frequencies.

In a radio apparatus, the band of a loop filter of a synthesizer in a blank channel searching state is narrower than the band in a communicating state. In addition, a radio wave environment is measured. A characteristic necessary for the radio apparatus is determined corresponding to the measured radio wave environment. The power is controlled corresponding to the performance of the radio apparatus. Thus, the power consumption is decreased. In addition, the efficiency of the output power is improved. In the radio apparatus, the current consumption of a power amplifier PA is measured. A matching circuit (LNA or MIX) of the antenna is adjusted with the measured result so as to decrease an antenna loss. In the radio apparatus, a DC offset is removed from the transmitted power and the reflected wave. When the DC offset is removed using an AC coupling capacitor, the deterioration of the frequency characteristic of the receiving portion is compensated with a capacitor in a digital signal process. In the radio apparatus, a transmission power detecting portion is structured as an IC chip. The transmission power detecting portion detects the transmission power corresponding to leakage currents in the power supply of the IC chip and the ground. Thus, when the power is detected, a power loss is suppressed. Consequently, the power consumption of the radio apparatus can be decreased.

A system and method to efficiently use a plurality of ‘receivers’ to monitor a larger plurality of ‘sources’ for audio content. Upon identifying that a source is active, one of the plural receivers is assigned to convey the content to a destination. All other receivers are prevented from monitoring that specific source for the duration of its activity, but continue to monitor the remaining sources. ‘Source’ includes any source of information containing audio content. ‘Receiver’ includes any device capable of selectively conveying such content, including physical switches, hardware or software multiplexers, microphones, radio receivers, or any other means of obtaining such content.

A tuner unit generates a local oscillation signal which is multiplied by a received first IF signal to change the frequency of the received first IF signal, and converts the frequency-changed first IF signal into a baseband signal. A demodulation unit detects the signal level of demodulated data, and notifies the signal level to a control unit. The control unit compares the signal level notified by the demodulation unit with a reference value stored in a storage unit, and if the signal level is equal to or smaller than the reference value, makes the tuner unit change the frequency of a local oscillation signal to be used for frequency conversion of the first IF signal and perform a channel selection in a next frequency range. Time taken to start providing a service can therefore be shortened.

The present invention relates to a quadrature divider which may be used in a phase locked loop or frequency synthesiser or with a single side band mixer. According to a preferred embodiment the divider takes a quadrature input and has a quadrature output. The divider has four analog mixers 1, 2, 3 and 4. The first two mixers 1, 2 take the in-phase quadrature input, while the second mixers 3, 4 take the quadrature-phase quadrature input. The outputs and feedback loops of the mixers are properly arranged such that the in-phase and quadrature-phase outputs of the divider have a determinisitic phase sequence relationship based on the phase sequence relationship of the corresponding quadrature inputs. Third order harmonics may be minimised or reduced by addition or subtraction of the mixer outputs. As the divider is able to take a quadrature input, there is no need for a dummy divider in the phase locked loop, thus saving space and power.

A channel tuning apparatus which improves operability by eliminating a need for a user to select a CATV mode and allows reliable channel tuning without misjudging the presence or absence of signals even if a frequency of a CATV broadcast is shifted. The channel tuning apparatus includes a tuner (2) for receiving signals from an antenna (1), a demodulation unit (3) for demodulating the received signals coming from the tuner (2), an input unit (6) for selecting a specific channel for the tuner (2), a detection unit (4) for determining receive mode, and a memory unit (5) for storing the detected data by the detection unit (4), in which the channel tuning apparatus is configured to, before performing automatic channel tuning, tune to a specific channel determined by the input unit (6), detect the receive mode and shift in the received frequency, and store them for use as initial data for automatic channel tuning.

Disclosed in a digital broadcasting receiver comprising first means for performing pre-scan processing for successively tuning in on channels previously set, to examine whether or not a received signal on each of the channels is of a predetermined quality or more, and temporarily registering the channel numbers of the channels on which the received signals are of the predetermined quality or more in a storage device as receivable channel candidates, and second means for performing normal scan processing for successively tuning in on the receivable channel candidates temporarily registered in the storage device by the first means, to acquire and register necessary channel information.

A television tuner that receives a television signal using a smart antenna includes a rescan unit that executes rescan; that is: that when an instruction that instructs direct selection of a reception channel on which a television signal is currently received is issued during reception of a television broadcast service, causes an antenna control section to vary or control the receiving direction of the smart antenna and causes a signal state detector section to detect the states of signals sampled in all receiving directions; and that if the state of a signal detected by the signal state detector section agrees with a predetermined signal state, preserves the receiving direction of the smart antenna in which the signal is sampled. Consequently, rescan can be executed for all the receiving directions of the smart antenna by performing a simple manipulation.

A tuner unit includes a scan-candidate registration unit that registers candidate frequencies to be scanned, a scan-frequency selection unit that selects frequencies to be scanned, a first scan unit that performs scanning on the basis of the frequencies to be scanned, a reception determination unit that determines whether channel signals can be received, a scan-candidate-frequency update unit that registers, as detected frequencies, frequencies of ones of the channel signals that can be received and eliminates ones of the candidate frequencies to be scanned within a predetermined range with its center at each of the detected frequencies, and a second scan unit that performs scanning on the basis of the updated candidate frequencies to be scanned. Even when the second scan unit performs scanning, the scan-candidate-frequency update unit performs the same process as described above.

The invention discloses an automatic channel selection module for a radio, which is arranged on a mobile terminal. The automatic channel selection module comprises a database module and a searching module, wherein, the searching module is used for searching broadcasting channels of corresponding radio stations in different cities in the database module. The invention further discloses a channel selection method of the automatic channel selection module for the radio, which comprises the following steps: S1, the mobile terminal records the listening frequencies of the current radio stations of departure places and the cities; S2, the mobile terminal acquires new city names by network terminal interaction while roaming occurs; and S3, the searching module searches corresponding listening channels in the cities retrieved by the same station captions in step 2 in the database module. In the invention, the mobile terminal can directly call frequency signals of the corresponding local radio stations while roaming occurs, so a user is not interrupted in listening when the radio searches the signals and can listen more smoothly.

A radio system operable to receive signals in a plurality of frequency bands includes a control module and an interface module whereby a user may store a plurality of presets from the bands. The interface module displays to the user a page of the presets for selection of a play frequency therefrom. The page includes frequencies from more than one band.

A system for radio scanning and signal generation including a direct digital synthesis (DDS) signal generator providing a signal within a first bandwidth; a frequency multiplier in signal communication with the DDS signal generator; the frequency multiplier adapted to convert the signal within the first bandwidth to a multiplied signal within a second bandwidth, wherein the second bandwidth encompasses a wider frequency range than the first bandwidth; a processor in communication with the DDS signal generator for programming the DDS signal generator to provide the signal within the first bandwidth; the processor further adapted to reprogram the DDS signal generator to alter the first bandwidth; a radio frequency (RF) port for transmitting the signal as a wideband signal.

When a satellite broadcasting receiving device 5 is initially set up, a receivable channel is searched for each satellite. In this search, a wider frequency acquisition range than a frequency acquisition range which is generally used is set for a QPSK demodulation IC 15, while the frequency of a PLL 9 is fixed. Then, in the wider frequency acquisition range, an offset is shifted by a frequency step Fstep′ by using a function for setting a frequency offset, the function being included in the QPSK demodulation IC 15. Thus, a signal search is carried out throughout a reception frequency range.

A television receiver is connected to a multi-directional antenna having multiple receiving directions for receiving a television signal by making one receiving direction active, and comprises a clock, a tuner, a memory for storing a receiving direction table having content containing channel numbers and a best receiving direction, and a microprocessor for controlling the receiver. Based on the time measured by the clock, the microprocessor renews the content of the table at a preset time, and outputs, to the antenna, a control signal to command a receiving direction for receiving one channel based on the renewed content of the table. The receiver can properly adapt to the variations in time of the receiving conditions of terrestrial broadcasts based on the renewed content of the table, and can automatically renew the content of the table in a time zone when a user does not view a television program.

A broadcast module includes a receiver for selecting the signal of a specific channel from the signals of a plurality of channels under control of a controller; a demodulator connected to the output of the receiver; a detector for detecting the signal-to-noise ratio of the signal selected by the receiver; and a comparator for comparing the signal-to-noise ratio detected by the detector with a predetermined level. The broadcast module can reduce the time required to specify a viewable cannel.

A receiver is provided capable of receiving both RDS (Radio Data System) and DARC (DAta Radio Channel) system FM multiplex broadcasting. An RDS signal demodulating circuit is provided with a PLL circuit which comprising a first frequency divider for dividing an output of a crystal oscillator, a phase comparator for inputting an output of the first frequency divider, a low-pass filter connected with the phase comparator, a VCO connected with the low-pass filter, and a second frequency divider for dividing an output of the VOC and outputting the divided output signal to the phase comparator. An output of the VCO is transmitted as a reference clock RDSCL for demodulation of an RDS signal.

A receiver and associated methods are described. The receiver comprises a first oscillator 14, a second oscillator 16, a controller 18 operable to control frequencies to which the first and second oscillators are tuned, and a discrimination circuit 24 operable to receive and monitor transmitted signals; wherein the discrimination circuit is configured to receive a signal at a first transmission frequency determined based on a first tuned frequency to which the first oscillator is tuned, and to determine, in a capture time period, whether data is being transmitted at the first transmission frequency; wherein the controller is configured to tune, in a tuning time period, the second oscillator to a second tuned frequency; and wherein the tuning time period is shorter than the capture time period.