Abstract: To provide a circuit arrangement for converting a preferably analog input signal from at least a receiver, particularly at least a UHF or VHF receiver, into a digital output signal, said circuit arrangement (100) comprising:

Abstract: Disclosed is a RF block of a mobile communication base station in which separated modules therein is implemented into one module, in which an antenna diagnosis function is performed by using a modem (control module) embedded therein, and in which implementation of a filter is simplified. The RF block of a mobile communication base station of the present invention has many advantages in that each of the separated modules therein is implemented into one module so that a degree of utility of a space is improved, and therefore, the number of components and a unit price is reduced, thereby curtailing a cost when configuring a system, in that a variable attenuator can vary an output level of the system so that a variable range thereof is wider than that implemented by a PCB circuit of a up-converter, and in that a control/alarm signal is processed by a modem so that it is easy to monitor the mobile communication base station upon operation thereof.

Abstract: A tuner, for example, for a television receiver, includes a UHF and a VHF section and a mixer oscillator stage. It is known that the VHF frequency band has to be split in at least two parts to handle the VHF signals. To that end, the mixer oscillator stage uses two separate VHF oscillators and a detector to switch tuned parts of the VHF section. In this way, the performance of the tuner is improved.

Abstract: A dual channel receiver (100) includes a front end bandpass filter (120) that has a front end bandwidth, a first mixer (130), a second mixer (135), and two essentially identical receiver back ends (190, 195). The front end bandpass filter splits a received signal into a first signal (121) and a second signal (122) of essentially equal signal strengths and provides out of band isolation between first and second signal outputs (123, 124). The first mixer is coupled to the first signal and to a high side injection signal (131), and generates a first mixer output signal (132). The second mixer is coupled to the second signal and to a low side injection signal (136), and generates a second mixer output signal (137). Each of the two essentially identical receiver back ends is coupled to one of the first and second mixer output signals.

Abstract: There is provided a television tuner including a first amplifier for amplifying received signals having frequencies of VHF-L and VHF-H bands, a first converter for converting a frequency of the received signals having been amplified by the first amplifier, a second amplifier for amplifying a received signal having a frequency of UHF band, a second converter for converting a frequency of the received signal having been amplified by the second amplifier, a signal transmitter for transmitting an operation switching signal by which the VHF-L band, the VHF-H band, or the UHF band is selected, a detector for detecting that none of the VHF-L and VHF-H bands is selected, based on data about the VHF-L and VHF-H bands, represented by the operation switching signal, and a driver for driving the second amplifier and pausing the first amplifier when the detector detects that none of the VHF-L and VHF-H bands is selected, and pausing the second amplifier and driving the first amplifier when the detector detects that one of

Abstract: A method of providing low energy consumption ultrafast lock time in a mobile communication system normally operating at slower lock times and requiring occasional ultrafast lock times when switching from the transmit mode to the receive mode and/or from the receive mode to the transmit mode. There are provided a normally operating PLL and a normally disabled DDS. Responsive to a requirement for the ultrafast lock time, the DDS is enabled and substituted for the PLL. Subsequently, responsive to removal of the requirement for the ultrafast lock time, the PLL is substituted for the DDS and the DDS is disabled. When the transmit and/or receive mode requires a frequency above the capability of the DDS, a mixer is added for mixing the output of the DDS with a signal having stable reference frequency to obtain a frequency equal to the sum of frequencies of the DDS output and the stable reference signal.