摘要:
A tunable filter design. The filter is implemented using transmission line sections as inductive and capacitive components. At least one capacitive component is a tunable capacitor. In some implementations, the tunable capacitor may be an interdigitated array of finger elements arranged so that the spacing between fingers may be adjusted. The design has a number of advantages including high capacitance for a given circuit area, small area for a given desired capacitance, mechanical stability, high self resonance frequency, and high quality factor.
摘要:
A signal handler providing high linearity in a small size, applicable across wide operating frequencies and bandwidths, while also adapted to preferred integrated circuit (IC) and printed circuit board technologies. In one implementation, a signal handling apparatus includes an input impedance transformer for receiving an input signal and matching an internal apparatus impedance, a splitter for providing N split signals, a number of signal processing circuits for processing the N split signals, a combiner for combining the N split signals into a combined signal, and output impedance transformer for receiving the combined signal and for matching the internal apparatus impedance to an output impedance of the apparatus. The apparatus may provide filtering, duplexing and other radio frequency signal processing functions. A tunable duplexer may be implemented using a vector inductor and tunable capacitor array with frequency dependent impedance transformers.
摘要:
In an embodiment, a circuit includes a variable group delay configured to delay a wideband input signal to obtain a delayed input signal; a wideband operational amplifier configured to determine an error signal based on a difference between the delayed input signal and a linearized power amplifier output; a feedback amplifier configured to amplify the error signal to obtain an amplified error signal; and a directional combiner configured to combine the amplified error signal with the power amplifier output to obtain the linearized power amplifier output.
摘要:
Embodiments provide for dramatically improved interference resistance in advanced communications applications, where the frequency range can exceed 1 GHz. Such embodiments may be implemented using wideband technology to provide a wideband compressive sampling architecture that is capable of superior interference rejection through RF front end cancellation.
摘要:
A system and method of adaptively correcting the excitation or receive coefficients for a phased array antenna. For a transmitting antenna, a sensor located in the near field of the antenna is used to sense the antenna transmission. A reference signal that represents the sensor response to a desired antenna transmission that is accomplished with predetermined excitation coefficients is determined. The magnitudes and phases of the excitation coefficients are modified in a predetermined manner to create a modified antenna transmission. An actual signal that represents the sensor response to the modified antenna transmission is then determined. The excitation coefficients are then corrected using the differences between the reference signal and the actual signal, such that the modified antenna transmission becomes closer to the desired antenna transmission. The method and system also apply to a receiving antenna.
摘要:
Apparatus and methods for variable capacitor arrays are provided herein. In certain configurations, an apparatus includes a variable capacitor array and a bias voltage generation circuit. The variable capacitor array includes a plurality of metal oxide semiconductor (MOS) variable capacitor cells, which include one or more pairs of MOS capacitors implemented in anti-parallel and/or anti-series configurations. In certain implementations, the MOS variable capacitor cells are electrically connected in parallel with one another between a radio frequency (RF) input and an RF output of the variable capacitor array. The bias voltage generation circuit generates bias voltages for biasing the MOS capacitors of the MOS variable capacitor cells.
摘要:
Apparatus and methods for variable capacitor arrays are provided herein. In certain configurations, an apparatus includes a variable capacitor array and a bias voltage generation circuit. The variable capacitor array includes a plurality of metal oxide semiconductor (MOS) variable capacitor cells, which include one or more pairs of MOS capacitors implemented in anti-parallel and/or anti-series configurations. In certain implementations, the MOS variable capacitor cells are electrically connected in parallel with one another between a radio frequency (RF) input and an RF output of the variable capacitor array. The bias voltage generation circuit generates bias voltages for biasing the MOS capacitors of the MOS variable capacitor cells.
摘要:
Embodiments include methods, systems, and apparatuses capable of dynamically and adaptively operating on wideband signals. Examples include state variable filters whose center frequencies can be tuned using variable gain blocks coupled to outputs of filter integrators. First- and second-order state variable filters may operate on signals in parallel and their outputs combined to produce a filtered output. Filters may be tuned to pass or reject signals depending on the application; sample applications include, but are not limited to: agile filtering; spectrum analysis; interference detection and rejection; equalization; direct intermediate-frequency transmission; and single-sideband modulation and demodulation.
摘要:
Apparatus and methods for vector inductors are provided herein. In certain configurations, an apparatus includes a vector inductor comprising a plurality of conductors arranged in a stack and separated from one another by dielectric. The conductors are tightly coupled to one another to provide a relatively high amount of mutual inductance. For example, adjacent conductors in the stack can be mutually coupled with a coupling coefficient k that is at least 0.5, or more particularly, 0.9 or greater. In certain implementations, the conductors are electrically connected in parallel with one another to provide the vector inductor with low resistance. However, tight coupling between the conductors in the stack can result in vector inductor having an overall inductance that is similar to that of a self-inductance of an individual conductor in the stack. The Q-factor of the vector inductor can be increased by the inclusion of additional conductors in the stack.
摘要:
Techniques for implementing tunable lumped element filters with transmission line sections. Transmission lines sections are used to implement one or more inductive or capacitance component elements of the filter. The filter is tunable by changing the dielectric constants of the transmission lines. In particular implementations there is an individual transmission line section for each lumped element component of a filter. Different filter circuits may be combined to provide a universal tunable filter assembly.