摘要:
A front end and a high frequency receiver (1) provided therewith are described, which front end comprises a quadrature low noise amplifier (2-1, 2-2) as a low noise amplifier. A high isolation between local oscillators (6-1, 6-2) and quadrature mixers (3-1, 3-2) is achieved thereby, reducing a DC offset at mixer outputs (7, 8). The quadrature low noise amplifier may be implemented as a differential class AB cascade arrangement of MOST or FET semiconductors (15). A low distortion receiver (1) having a high linearity is the result.
摘要:
A quadrature coupled controlled oscillator comprising a first and a second circuit module, each of the circuit modules (100 and 100′) comprising an astable multivibrator circuit (103). The first circuit module is coupled with the second circuit module and the second circuit module is cross coupled with the first circuit module. Each of the circuit modules (100 and 100′) comprises a first and a second Voltage Controlled Current Source (101) (VCCS). In each of the circuit modules, each VCCS is coupled to a phase shifter (102) for shifting the phase of a current (110) supplied by the VCCS to a resonator (104) included in that circuit module. A communication arrangement (300) for communicating via a bi-directional communication channel (304), comprises an oscillator (303) as described above for generating a periodic signal. A receiving module (301) generates an output signal from the periodic signal and a receiving signal received from the channel (304). The arrangement further comprises an emission module (302) for generating an emission signal for emitting to the channel from the periodic signal and an input signal.
摘要:
A front end and a high frequency receiver (1) provided therewith are described, which front end comprises a quadrature low noise amplifier (2-1, 2-2) as a low noise amplifier. A high isolation between local oscillators (6-1, 6-2) and quadrature mixers (3-1, 3-2) is achieved thereby, reducing a DC offset at mixer outputs (7, 8). The quadrature low noise amplifier may be implemented as a differential class AB cascade arrangement of MOST or FET semiconductors (15). A low distortion receiver (1) having a high linearity is the result.
摘要:
The invention relates to a method for modulating an output voltage of a transmitter circuit comprising a voltage controlled oscillator, a digital/analog converter and an antenna circuit, the method comprising the method comprising sending an output signal of sufficient power from the voltage controlled oscillator directly to the antenna circuit and directly modulating a frequency of the output signal of the voltage controlled oscillator. The invention furthermore relates to a transmitter circuit comprising a voltage controlled oscillator having a tank circuit, a digital/analog converter and an antenna circuit, wherein the voltage controlled oscillator is adapted to send an output signal of sufficient power directly to the antenna circuit and wherein the digital/analog converter is arranged to modulate an output frequency of the voltage controlled oscillator. A capacitive load circuit may be connected to the tank circuit or a crystal oscillator circuit of the voltage controlled oscillator for modulating the frequency of the voltage controlled oscillator.
摘要:
A front end and a high frequency receiver provided therewith are described, which front end comprises a quadrature low noise amplifier as a low noise amplifier. A high isolation between local oscillators and quadrature mixers is achieved thereby, reducing a DC offset at mixer outputs. The quadrature low noise amplifier may be implemented as a differential class AB cascode arrangement of MOST or FET semiconductors. A low distortion receiver having a high linearity is the result.
摘要:
A filter (3) is described, which filter is provided with field effect (FET) capacitors (M1-32; M′1-32) arranged for controlling their respective capacity values, each such FET capacitor (M1-32; M′1-32) having a source (S) and a drain (D). The source (S) and the drain (D) of each FET capacitor (M1-32; M′1-32) are coupled to one another. The filter acting as an impedance transformer is a passive low power consuming and tunable filter, such as for a radio frequency (RF) receiver. It occupies only a very small area, while integrated on chip.
摘要:
A low power frequency synthesizer circuit for a radio transceiver, the synthesizer circuit comprising: a digital controlled oscillator configured to generate an output signal (Fo) having a frequency controlled by an input digital control word (DCW); a feedback loop connected between an output and an input of the digital controlled oscillator, the feedback loop configured to provide the digital control word to the input of the digital controlled oscillator from an error derived from an input frequency control word (FCW) and the output signal; and a duty cycle module connected to the digital controlled oscillator and the feedback loop, the duty cycle module configured to generate a plurality of control signals to periodically enable and disable the digital controlled oscillator for a set fraction of clock cycles of an input reference clock signal (RefClock).
摘要:
A frequency divider providing an odd integer division factor comprising a binary counter (10) providing an even integer division factor, which is the first even number smaller than the odd division factor, the binary counter having a clock input for receiving a periodical clock signal (Ck) having a frequency. The circuit further comprises an end of count circuit (20) coupled to the binary counter and generating an End Of Count signal (EOC) for a clock (Ck) period after every even integer number periods of the clock signal (Ck), the end of count signal (EOC) being inputted to an input (IN) of the counter (10). The circuit further includes an output generator (30) coupled to the binary counter and to the clock signal (Ck), the output generator (30) generating an output signal (OUT) having a frequency which is substantially equal with the frequency of the frequency signal (Ck) divided by the odd division factor.
摘要:
Devices (1) for exchanging ultra wide band signals comprise frequency translating stages (20,30) for frequency translating signals and oscillating stages (40) for supplying main inphase/quadrature oscillation signals to the frequency translating stages (20,30). By providing the oscillating stages (40) with polyphase filters (43,44) for reducing harmonics in oscillation signals, the main oscillation signals will be sufficiently clean. The oscillating stages (40) comprise mixers (46) for converting first inphase/quadrature oscillation signals and second inphase/quadrature oscillation signals into the main oscillation signals. The polyphase filters (43,44) may be located before and after the mixers (46). Frequency selectors (45) replace prior art multiplexers located after the mixers (46). Such frequency selectors (45) comprise multiplexers (126,127) for supplying the second inphase/quadrature oscillation signals, with a combination of these second oscillation signals corresponding with a positive frequency, a negative frequency or a zero frequency, and comprise coders (125) for controlling the multiplexers (126,127).
摘要:
A frequency-hopping arrangement comprises a basic-frequency branch (DIV1), an offset-frequency branch (DIV2, DIV3, SCC), and a controllable frequency converter (SBM, FSC). The basic-frequency branch (DIV1) receives an oscillator signal (OS) having an oscillator-signal frequency (7920 MHz). The basic-frequency branch has a frequency-division factor (/2) so as to provide a basic-frequency signal (BF) having a basic frequency (+3960 MHz) that is the oscillator-signal frequency divided by the frequency-division factor. The offset-frequency branch (DIV2, DIV3, SCC) receives the same oscillator signal (OS). The offset-frequency branch has a different frequency-division factor (/3, /5) so as to provide an offset-frequency signal (OF) having an offset frequency (+528 MHz) that is the oscillator-signal frequency divided by the different frequency-division factor. The controllable frequency converter (SBM, FSC) provides a frequency-hopping signal (FHS) having a frequency (cl*+3960+c2*+528 MHz) that is a linear combination of the basic frequency and the offset frequency with at least one coefficient (c2) that varies as a function of a hopping-control signal (HCS).