Optimal low power complex filter
AssigneesKing Fahd University of Petroleum and Minerals, King Abdulaziz City for Science and Technology
InventorHussain Alzaher
Life of this patent
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Abstract
The optimal low power complex filter, as a second order complex filter, is based on current amplifiers (CAs) and is utilized to implement a 4th order current-mode filter that can be used for intermediate frequency (IF) applications, such as, for example, low-IF Bluetooth receivers. Fabricated in a standard 0.18 μm CMOS technology, experimental results show that the present design offers improved characteristics over the existing solutions in terms of power consumption and spurious-free dynamic range (SFDR). The 4th order filter exhibits in-band SFDR of 65.8 dB while consuming only 1 mW.
Claims12
An optimal low power complex filter, comprising:
- a plurality of current amplifiers (CAs) configured as a cascade of current mode (CM) complex integrators to provide a fully differential biquad electronic filter circuit, the electronic filter circuit including input terminals to receive in-phase (I) and quadrature (Q) input signals for filter processing of the input signals, and including output terminals to provide filtered I and Q output signals;
- and
- a plurality of series RC circuits, each RC circuit having a resistor's lead connected to a respective CA's input and a capacitive lead connected to ground.
An optimal low power complex filter, comprising:
- a plurality of type 2 current conveyers (CCII), each CCII being configured as a transconductance amplifier (TCA) having a Y input, an X input, and a plurality of current outputs, the TCAs being configured in multiple stages, a first stage of said TCAs to receive in-phase (I) and quadrature (Q) input signals for filter processing, each subsequent stage of said TCAs being connected in a feedback arrangement with a corresponding previous stage, and a last stage to provide in-phase (I) and quadrature (Q) filtered output signals;
- and
- for each stage, a capacitor C connected between said Y input and ground, and a resistor R connected between said X input and ground.
Dependencies are inferred from the claim text.