Abstract:
A series injection device includes a power splitter coupled to two or more lines of an AC power system. The power splitter includes a coupling transformer for each phase of a single phase or polyphase AC circuit that includes the two or more lines. Each of the coupling transformers couples one of the phases of the two or more lines. The power splitter is configured to inject a first voltage of a first polarity into one or more of the two or more lines and inject a second voltage of a second polarity opposite the first polarity into at least one of the two or more lines via the same coupling transformers used to inject the first voltage. The first and the second voltages are controllable, and may or may not be independently variable.
Abstract:
Certain aspects of the present disclosure provide circuits for generating high accuracy millimeter wave or radio frequency (RF) wideband in-phase (I) and quadrature (Q) oscillating signals having acceptable amplitude and phase mismatch over process, voltage, and temperature (PVT) variations with reduced cost, area, and power consumption. In one example apparatus, a polyphase filter having a first stage (602) and a second stage (604) is provided. Each stage comprises resistive elements (503) and capacitive elements (505). Certain aspects of the present disclosure provide for intentional resistive and/or capacitive value mismatch between the resistive or capacitive values of one or multiple stages such that the phase mismatch between the resulting I and Q signals may be reduced without degrading the amplitude mismatch. Certain aspects of the present disclosure provide for replacing the resistive elements in at least one stage with transistors (508) operating in the triode region, where the on-resistance is controlled by a feedback network (506).
Abstract:
An l/Q network (700) comprising an all-pass filter (401) which is adapted to receive differential input signals at a differential input port (120) with first (131) and second (132) terminals and to output differential I and Q voltage signals at differential I and Q output ports with respective first (111, 122) and second (112, 121) terminals. The all-pass filter (401) is adapted to receive the differential input signals as current signals, and in the all-pass filter the differential input port (130) is also arranged to be one of the differential I and Q output ports.
Abstract:
A composite band-pass filter receives a quadrature input signal and passes an intermediate frequency signal while attenuating all other signals including an undesired image signal. The composite band-pass filter is comprised of a continuous time polyphase filter and a discrete time polyphase filter and can amplify signals. The amplification is distributed through out the composite band-pass filter and the amount of amplification may be selected by control signals. The composite band-pass filter has improved dynamic range and noise characteristics, selectable amplification and replaces an external crystal filter.
Abstract:
A method and device are described for generating two output signals (I; Q) each substantially identical to a square-wave input signal (A) from a local oscillator (2), wherein the first output signal (I) may have a certain time shift with respect to the input signal (A), and wherein the second output signal (Q) is shifted over T1/4 [mod T1] with respect to the first output signal (I), T1 being the period of the input signal (A). To generate the first output signal (I), Fourier components (S1((1), S3((3), S5((5), S7((7), S9((9), S11((11) etc) of the input signal are combined. To generate the second output signal (Q), Fourier components (S1((1), S5((5), S9((9) etc) of the input signal are phase shifted over +90 DEG while Fourier components (S3((3), S7((7), S11((11) etc) of the input signal are phase shifted over -90 DEG , and the thus shifted Fourier components of the input signal are combined.
Abstract:
A system for an eight-phase 45 DEG polyphase filter with amplitude matching, where a full eight-phase 45 DEG split may be achieved by tying together the inputs (V>i1 i2
Abstract:
A pi /2 phase shifter generates first and second signals (SIGa, SIGb) of equal amplitude and different phases and first and second inverted signals (/SIGa, /SIGb) whose phases are opposite to those of the first and second signals, depending on an input signal. A first output signal (SIGOa) is produced by the addition of the first signal (SIGa) and the second signal (SIGb), and a second output signal (SIGOb) is produced by the addition of the first signal (SIGa) and the second inverted signal (/SIGb). The first output signal (SIGOa) and the second output signal (SIGOb) correspond to the diagonals of a rhombus formed of a vector (v3) indicating the first signal and a vector (v4) indicating the second signal, respectively, since the first and second signals (SIGa, SIGb) have the same amplitude. Consequently, the phase difference between the first and second output signals from the pi /2 phase shifter is set accurately at pi /2 irrespective of whether the phase difference between the first and second signals is pi /2.