Abstract: The present invention relates to a polar modulation apparatus and method, in which a polar-modulated signal is generated based on separately processed phase modulation (PM) and amplitude modulation (AM) components of an input signal. An amplified polar modulated output signal is generated in accordance with the phase modulation and amplitude modulation components by using a differential power amplifier circuitry(30) and supplying an amplified phase modulation component to a differential input of the differential power amplifier circuitry(30). A bias input of the differential power amplifier circuitry(30) is controlled based on the amplitude modulation component, so as to modulate a common-mode current of the differential power amplifier circuitry(30). Thereby, a new concept of a polar modulator with static DC-DC converter and power and/or efficiency and/or linearity controlled output power amplifier can be achieved.

Abstract: A flash analog to digital converter and a method and system for dynamically calibrating the flash analog to digital converter. The analog to digital converter may include a track and hold circuit and a plurality of comparators. The analog to digital converter may also include an under-sampling circuit configured to convert a digitized reference signal into an under-sampled digitized reference signal with a frequency of the calibration frequency divided by a positive number M. The under-sampling circuit may be further configured to calibrate a subsequent signal based on the under-sampled digitized reference signal.

Abstract: An amplifier, mixer, and method for input impedance matching and linearization. The transconductor includes a first differential transistor and a second differential transistor, including a first differential source and a second differential source electrically connected at a source node. The transconductor includes a pair of transmission lines including a first line of the pair of transmission lines electrically connected to the first of the two differential voltage inputs and a second line of the pair of transmission lines electrically connected to the second of the two differential voltage inputs. The pair of transmission lines is electrically connecting the two differential voltage inputs at a common node. The transconductor also includes a linearization unit including one or more linearization transistors. The one or more linearization transistors include a linearization gate electrically connected to the common node. The linearization unit is configured to supply a virtual ground at the source node.

Abstract: A flash analog to digital converter and a method and system for dynamically calibrating the flash analog to digital converter. The analog to digital converter may include a track and hold circuit and a plurality of comparators. The analog to digital converter may also include an under-sampling circuit configured to convert a digitized reference signal into an under-sampled digitized reference signal with a frequency of the calibration frequency divided by a positive number M. The under-sampling circuit may be further configured to calibrate a subsequent signal based on the under-sampled digitized reference signal.

Abstract: The present invention relates to an oscillator circuit and a method of controlling the oscillation frequency of an in-phase signal and a quadrature signal. First oscillator means (2) with a first differential oscillator circuit and a first differential coupling circuit are provided for generating the quadrature signal. Furthermore, second oscillator means (4) with a second differential oscillator circuit and a second differential coupling circuit are provided for generating the in-phase signal. A frequency control means is provided for varying the oscillation frequency of the in-phase signal and the quadrature signal by controlling at least one of a common-mode current and a tail current of the first and second oscillator means. Thereby, a high-frequency IQ oscillator with high linearity is obtained.

Abstract: The present invention relates to a polar modulation apparatus and method, in which a polar-modulated signal is generated based on separately processed phase modulation (PM) and amplitude modulation (AM) components of an input signal. An amplified polar modulated output signal is generated in accordance with the phase modulation and amplitude modulation components by using a differential power amplifier circuitry(30) and supplying an amplified phase modulation component to a differential input of the differential power amplifier circuitry(30). A bias input of the differential power amplifier circuitry(30) is controlled based on the amplitude modulation component, so as to modulate a common-mode current of the differential power amplifier circuitry(30). Thereby, a new concept of a polar modulator with static DC-DC converter and power and/or efficiency and/or linearity controlled output power amplifier can be achieved.

Abstract: The present invention relates to a polar modulation apparatus and method, in which a polar-modulated signal is generated based on separately processed phase modulation (PM) and amplitude modulation (AM) components of an input signal. An amplified polar modulated output signal is generated in accordance with the phase modulation and amplitude modulation components by using a differential power amplifier circuitry and supplying an amplified phase modulation component to a differential input of the differential power amplifier circuitry. A bias input of the differential power amplifier circuitry is controlled based on the amplitude modulation component, so as to modulate a common-mode current of the differential power amplifier circuitry. Thereby, a new concept of a polar modulator with static DC-DC converter and power and/or efficiency and/or linearity controlled output power amplifier can be achieved.

Abstract: The present invention relates to an improved PTAT current source and a respective method for generating a PTAT current. Opportune collector currents are generated and forced in two transistors exploiting the logarithmic relation between the base-emitter voltage and the collector current of a transistor. A resistor senses a voltage difference between the base-emitter voltages of the two transistors, which can have either the same or different areas. A fraction of the current flowing through the resistor is forced into a transistor collector and mirrored by an output transistor for providing an output current. By this principle an all npn-transistor PTAT current source can be provided that does not need pup transistors as in conventional PTAT current sources. The invention is generally applicable to a variety of different types of integrated circuits needing a PTAT current reference, especially in modern advanced technologies as InP and GaAs where p-type devices are not available.

Abstract: The present invention relates in general to transferring the envelope information of a polar modulated signal to a varying pulsewidth signal, while the phase modulation is direct transferred to the phase modulation of this PWM signal. Accordingly, the resultant signal is a PWM-PPM-signal. Such a signal can efficiently amplified by use of switching amplifying stages. By the present invention four pre-distorted baseband signals are applied basically to 4 linear RF mixers and a two adders, which are, the only needed external RF building blocks to build the modulator according to the invention. That is, the basic idea of the invention resides in the way of modulation of the four baseband signals and the way of combining of the RF modulated signals.

Abstract: The present invention relates in general to transferring the envelope information of a polar modulated signal to a varying pulsewidth signal, while the phase modulation is direct transferred to the phase modulation of this PWM signal. Accordingly, the resultant signal is a PWM-PPM-signal. Such a signal can efficiently amplified by use of switching amplifying stages. By the present invention four pre-distorted baseband signals are applied basically to 4 linear RF mixers and a two adders, which are, the only needed external RF building blocks to build the modulator according to the invention. That is, the basic idea of the invention resides in the way of modulation of the four baseband signals and the way of combining of the RF modulated signals.

Abstract: A BALUN circuit (20) for low voltage operation for receiving single ended input signal at an input terminal (24) and providing a differential output signal across a pair of output terminals (OUT+, OUT?) is disclosed. The BALUN circuit (20) comprises a first branch including an input terminal (24) for receiving a single ended input voltage signal (RFin), a transistor (Q1), a resistance (R1) (28), a resistance (RL), and an output terminal (OUT+). A second branch includes a transistor (Q3), a resistance (RL) and an output terminal (OUT?). An operational amplifier (26) maintains current flowing through the resistances RL in the first and second branches substantially equal to each other, in dependence upon the output voltage signal across the output terminals (OUT+, OUT?).

Abstract: The present invention relates to an improved PTAT current source and a respective method for generating a PTAT current. Opportune collector currents are generated and forced in two transistors exploiting the logarithmic relation between the base-emitter voltage and the collector current of a transistor. A resistor senses a voltage difference between the base-emitter voltages of the two transistors, which can have either the same or different areas. A fraction of the current flowing through the resistor is forced into a transistor collector and mirrored by an output transistor for providing an output current. By this principle an all npn-transistor PTAT current source can be provided that does not need pup transistors as in conventional PTAT current sources. The invention is generally applicable to a variety of different types of integrated circuits needing a PTAT current reference, especially in modern advanced technologies as InP and GaAs where p-type devices are not available.

Abstract: A mixer circuit (102) for use in radio frequency (RF) equipment is disclosed. The mixer comprises a current source (Io) and a differential amplifier (Q1, Q2) connected to the current source and having input terminals (RF+, RF?) for receiving an RF input signal and output terminals (IF+, IF?) for providing an intermediate frequency signal. A local oscillator signal (LO) is applied to a transistor (Q3) connected in parallel with the differential amplifier to adjust the current flowing in the differential amplifier such that the differential output signal contains components having frequencies at the sum and difference frequencies of the RF and local oscillator signals. Emitter degeneration resistors (R1) and a transistor Q4 for diverting part of the current to the supply improve the linearity of the mixer.

Abstract: A sub-harmonic mixer circuit having an input stage (52) and a current modulating stage (64 is disclosed. The input stage (52) receives an RF input signal (RF+, RF?) at a first frequency and generates output currents (il , i2) varying in dependence upon the Rf input signal. The current modulating stage (64) comprises a first transistor (Q3) for receiving a first local oscillator signal (LO0) respective and a second transistor (Q4) for receiving a second local oscillator signal (LO180), 180 degrees out of phase with the first local oscillator signal, such that a modulating current signal (iO), having twice the local oscillator frequency is superimposed onto the output currents.

Abstract: The present invention relates to a polar modulation apparatus and method, in which a polar-modulated signal is generated based on separately processed phase modulation (PM) and amplitude modulation (AM) components of an input signal. An amplified polar modulated output signal is generated in accordance with the phase modulation and amplitude modulation components by using a differential power amplifier circuitry (30) and supplying an amplified phase modulation component to a differential input of the differential power amplifier circuitry (30). A bias input of the differential power amplifier circuitry (30) is controlled based on the amplitude modulation component, so as to modulate a common-mode current of the differential power amplifier circuitry (30). Thereby, a new concept of a polar modulator with static DC-DC converter and power and/or efficiency and/or linearity controlled output power amplifier can be achieved.

Abstract: A subharmonic mixer circuit having an input stage (52) and a current modulating stage (64) is disclosed. The input stage (52) receives an RF input signal (RF+, RF?) at a first frequency and generates output currents (i1, i2) varying in dependence upon the Rf input signal. The current modulating stage (64) comprises a first transistor (Q3) for receiving a first local oscillator signal (LOO) respective and a second transistor (Q4) for receiving a second local oscillator signal (LOI 80), 180 degrees out of phase with the first local oscillator signal, such that a modulating current signal (i0), having twice the local oscillator frequency, is superimposed onto the output currents.

Abstract: A BALUN circuit (20) for low voltage operation for receiving single ended input signal at an input terminal (24) and providing a differential output signal across a pair of output terminals (OUT+, OUT?) is disclosed. The BALUN circuit (20) comprises a first branch including an input terminal (24) for receiving a single ended input voltage signal (RFin), a transistor (Q1), a resistance (R1) (28), a resistance (RL), and an output terminal (OUT+). A second branch includes a transistor (Q3), a resistance (RL) and an output terminal (OUT?). An operational amplifier (26) maintains current flowing through the resistances RL in the first and second branches substantially equal to each other, in dependence upon the output voltage signal across the output terminals (OUT+, OUT?).