Abstract: A device includes a controller and an adaptive continuous-time filter that includes a control input and a first array of elements. The controller generates a digital word responsive to a time constant and compares a select bit of the digital word to a corresponding reference word to generate a control bit. The controller includes a duplicate array of elements, and applies the control bit to an adjustable element of the duplicate array of elements to modify the time constant. The controller provides the output word to the control input of the adaptive continuous-time filter to generate a filter response that accounts for effects of semiconductor process variation in the first array of elements.

Abstract: A device includes a controller and an adaptive continuous-time filter that includes a control input and a first array of elements. The controller generates a digital word responsive to a time constant and compares a select bit of the digital word to a corresponding reference word to generate a control bit. The controller includes a duplicate array of elements, and applies the control bit to an adjustable element of the duplicate array of elements to modify the time constant. The controller provides the output word to the control input of the adaptive continuous-time filter to generate a filter response that accounts for effects of semiconductor process variation in the first array of elements.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semi-conductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: This invention provides a dual-modality system for performing characterization and imaging of tissue, tumors, structures, lesions, and ablations under investigation. Specifically, the invention couples ultrasound technology comprising at least two focused ultrasound beams for vibrating target tissues located at the focal point of the ultrasound beams intersection with a radio frequency system for measuring the response of the target tissues. The ultrasound system vibrates the target tissues while the reflected radio frequency energy is transmitted into the target tissues. When reflected, the main carrier tone of the reflected radio frequency energy is cancelled and analysis is performed on the remaining sideband frequencies.

Abstract: This invention provides a dual-modality system for performing characterization and imaging of tissue, tumors, structures, lesions, and ablations under investigation. Specifically, the invention couples ultrasound technology comprising at least two focused ultrasound beams for vibrating target tissues located at the focal point of the ultrasound beams intersection with a radio frequency system for measuring the response of the target tissues. The ultrasound system vibrates the target tissues while the reflected radio frequency energy is transmitted into the target tissues. When reflected, the main carrier tone of the reflected radio frequency energy is cancelled and analysis is performed on the remaining sideband frequencies.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semi-conductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semiconductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semiconductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semiconductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: A multi-modality system and method for performing screening/detection, imaging and diagnosis/characterization of materials and objects in dense compressive media, such as in medical soft tissue applications, is disclosed. Medical tissue applications include but are not limited to the detection and diagnosis of breast tumors. Generally, the present invention involves coupling an ultrasound subsystem for exciting target tissues with a microwave subsystem for measuring the response, imaging and diagnosing the target tissues.

Abstract: A multi-modality system and method for performing screening/detection, imaging and diagnosis/characterization of materials and objects in dense compressive media, such as in medical soft tissue applications, is disclosed. Medical tissue applications include but are not limited to the detection and diagnosis of breast tumors. Generally, the present invention involves coupling X-ray mammography screening devices and methods with a system and method for further, real-time diagnosis of the X-ray results comprising an ultrasound subsystem for exciting target tissues and a microwave subsystem for measuring the response, imaging and diagnosing the target tissues.

Abstract: A multi-modality system and method for performing detection, characterization and imaging of materials and objects in dense compressive media, such as in medical soft tissue applications, is disclosed. Medical tissue applications include but are not limited to the detection and diagnosis of breast tumors. Generally, an ultrasound subsystem is employed to excite a region in the dense compressive media and a microwave subsystem is employed to collect detection, characterization and imaging information from the excited region. In one preferred embodiment, multiple focused oscillating high-frequency ultrasound wave beams are transmitted into the media. The resultant low beat-frequency wave creates a force inducing motion in the materials and objects in the media. A radio-frequency microwave subsystem detects that motion and produces images based upon the Doppler effects of the excited materials and objects.

Abstract: A mixer is disclosed having an output stage with an amplifier or gain device configured in a feedback loop to maintain a virtual ground at the input to the gain device. The gain device provides significant dynamic range, gain, and the appropriate impedance matching to insure a low noise output signal of a desired magnitude. Use of an amplifying output stage removes the dependence between mixer gain and mixer configuration, such as mixer bias resistor value, while concurrently overcome undesirable flicker noise that results from use of active devices in the mixer bias structure. A stable virtual ground at the mixer output and gain device input provides linearity over frequency. The gain device may comprises an operational amplifier or trans-resistance/trans-conductance device.

Abstract: A DC-offset cancellation system for a wireless receiver is disclosed. The DC-offset cancellation system comprises an amplifier and an impedance inverter configured to transform inductance applied to a received signal to a capacitance.

Abstract: A direct conversion radio-frequency (RF) receiver includes a controller and an adaptive continuous-time filter. The adaptive continuous-time filter receives a multiple-bit control signal generated by the controller to adjust a characteristic of the continuous-time filter. The controller generates the multiple-bit control signal in response to process variation in the semiconductor material used to implement the controller and the adaptive continuous-time filter. A method for tuning an adaptive continuous-time filter comprises determining a RC time constant, converting the RC time constant to a digital word, comparing a select bit of the digital word to a respective bit of a predetermined reference word to generate a control bit, applying the control bit to an adjustable element to modify the RC time constant, repeating the determining, converting, comparing and applying steps until the control bits generate an output word and providing the output word to the adaptive continuous-time filter.

Abstract: According to one exemplary embodiment, a digitally controlled oscillator includes a capacitive tuning network, where the capacitive tuning network controls a frequency of an output signal of the digitally controlled oscillator. The capacitive tuning network includes a switched capacitor array, where a change of a first capacitance of the switched capacitor array causes the capacitive tuning network to change by a second capacitance, and where the first capacitance is larger than the second capacitance. According to this exemplary embodiment, the capacitive tuning network further includes a first capacitor coupled in parallel with the switched capacitor array. The first capacitor has a third capacitance, which is larger than the first capacitance. The capacitive tuning network further includes a second capacitor coupled in series with the first capacitor and the switched capacitor array. The second capacitor can have a fourth capacitance, where the third capacitance is larger than the fourth capacitance.

Abstract: A low-noise filter for a wireless receiver is disclosed. The low-noise filter comprises an amplifier and a filter comprising a frequency dependent negative resistance implemented using a general impedance converter to realize a bi-quad filter. The low-noise filter is implemented such that noise generated by the filter when an in-band signal is processed is prevented from appearing at the output of the amplifier stage.