Abstract: A method and apparatus for mitigating the beam squint effect in a wideband wireless communication device involving a phased antenna array. Time delay units are operated in series with phase shifters to apply phase shifts to signals fed to or received from antenna elements. The array may be subdivided into sub-arrays each associated with its own time delay unit, and with each antenna element associated with its own phase shifter. The phase shifters are operated to compensate for location mismatch between time delay units and antenna elements, and also to compensate for practical limitations of the time delay units, such as length and quantization limitations.

Abstract: A method and apparatus for mitigating the beam squint effect in a wideband wireless communication device involving a phased antenna array. Time delay units are operated in series with phase shifters to apply phase shifts to signals fed to or received from antenna elements. The array may be subdivided into sub-arrays each associated with its own time delay unit, and with each antenna element associated with its own phase shifter. The phase shifters are operated to compensate for location mismatch between time delay units and antenna elements, and also to compensate for practical limitations of the time delay units, such as length and quantization limitations.

Abstract: A control circuit is disclosed for controlling operation of a radio frequency (RF) transistor. The control circuit has a first sub-circuit that accepts a reference voltage and a reference current. The control circuit has a second sub-circuit with a plurality of stacked transistors coupled between the first sub-circuit and ground, and a resistor ladder coupled between the first sub-circuit and an output port of the control circuit. The first sub-circuit provides the reference current to flow through the stacked transistors, and sets a total voltage drop across the stacked transistors equal to the reference voltage. The first sub-circuit also sets a total voltage drop across the resistor ladder equal to the reference voltage. Each rung of the resistor ladder is coupled to control an operating voltage of a stacked transistor, to cause each stacked transistor to operate with similar control conditions.

Abstract: A control circuit is disclosed for controlling operation of a radio frequency (RF) transistor. The control circuit has a first sub-circuit that accepts a reference voltage and a reference current. The control circuit has a second sub-circuit with a plurality of stacked transistors coupled between the first sub-circuit and ground, and a resistor ladder coupled between the first sub-circuit and an output port of the control circuit. The first sub-circuit provides the reference current to flow through the stacked transistors, and sets a total voltage drop across the stacked transistors equal to the reference voltage. The first sub-circuit also sets a total voltage drop across the resistor ladder equal to the reference voltage. Each rung of the resistor ladder is coupled to control an operating voltage of a stacked transistor, to cause each stacked transistor to operate with similar control conditions.

Abstract: A mixer circuit for downconverting a radio frequency signal to a lower (intermediate) frequency signal or upconverting an intermediate frequency signal to a radio frequency signal. The mixer circuit in downconversion mode has a single-ended radio frequency input and an intermediate frequency output. A transistor is provided that has a base that receives the radio frequency input, a collector, and a common emitter. A transformer is provided that has a primary winding AC coupled to ground and first and second secondary windings. The collector of the transistor is coupled to the primary winding. A first transistor pair and a second transistor pair are provided, each having a first and second transistor, and each transistor having a base, a collector and an emitter. The emitters of the first transistor pair are coupled together and to the first secondary winding of the transformer. The emitters of the second transistor pair are coupled together and to the second secondary winding of the transformer.

Abstract: A low noise radio frequency amplifier is switchable between a low gain state and a high gain state. A first, common-emitter transistor is active in the high gain state and inactive in the low gain state. The first transistor has a base coupled to a radio frequency input and a first bias input, an emitter coupled to ground, and a collector coupled to an amplified radio frequency output. A second, common-base transistor is active in the low gain state and inactive in the high gain state. The second transistor has an emitter coupled to the radio frequency input, a base coupled to a second bias input, and a collector coupled to the amplified radio frequency output.

Abstract: A linear gain controlled amplifier comprising a differential transistor pair having an input and an output. The input is connected to a current supply which includes both AC and DC components. A voltage is derived which is proportional to the DC current component and this is compared with a control signal to produce an error signal which is supplied to the gain control terminals of the differential transistor pair. Traditionally, gain control has been implemented using a closed loop consisting of a power detector, a loop filter and a gain control element. The output of the power detector is compared with a reference voltage in a comparator, the output of which is filtered by the loop filter and applied to a control input of the gain control element. Most power detectors are either inaccurate or expensive and elaborate and may exhibit a control error of several decibels.

Abstract: The functionality of a variable gain controlled amplifier and a tree mixer are combined to provide a variable gain controlled mixer. In constructing the combination, both the current-to-voltage conversion output stage of the mixer, and the voltage-to-current conversion input stage of the variable gain amplifier are removed. Both the variable gain stage and the mixing stage are connected in parallel to modify the input current. Other configurations are provided, including a single balanced mixer, and a folded mixer.

Abstract: A voltage controlled oscillator has a cross-coupled negative resistance cell formed as an integrated circuit connected to off-chip components of a high-Q resonant tank circuit. To counteract spurious oscillations brought about by package parasitics caused by the interconnection of the chip to the external components, the cell is provided with a degeneration impedance. Typically, a pure inductor is used if all the elements of the tank circuit are off-chip. In a case where the tank circuit includes an on-chip fixed capacitor, the degeneration impedance may take the form of a capacitor.

Abstract: A quadrature downconversion stage in a radio frequency receiver compensates for leakage from the quadrature local oscillator to the input of the stage by deriving first and second feedback signals from the quadrature local oscillator. The first feedback signal is 180.degree. out of phase with the in-phase component of the signal supplied to the input of the stage and the second feedback signal is 180.degree. out of phase with the quadrature component of the signal supplied to the input of the stage. The invention reduces or cancels a d.c. offset that can appear at the output of the stage. Another advantage is the reduction of re-radiated signals resulting from the local oscillator leakage. The invention is particularly applicable to direct converters.