Abstract:
A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.
Abstract:
A circuit comprises a Sallen-Key filter, which includes a source follower that implements a unity-gain amplifier; and a programmable-gain amplifier coupled to the Sallen-Key filter. The circuit enables programmable gain via adjustment to a current mirror copying ratio in the programmable-gain amplifier, which decouples the bandwidth of the circuit from its gain settings. The programmable-gain amplifier can comprise a differential voltage-to-current converter, a current mirror pair, and programmable output gain stages. The Sallen-Key filter and at least one branch in the programmable-gain amplifier can comprise transistors arranged in identical circuit configurations.
Abstract:
A circuit comprises a first amplifier coupled to a first and a second node; a differential capacitive load coupled to the first and the second node, the differential capacitive load coupled between drains of transistors in a cross coupled transistor circuit; a current mirror coupled to a source of each transistor; and a capacitor coupled between the sources of the transistors. A plurality of amplifiers can be coupled to the differential capacitive load, wherein each amplifier comprises a clock-less pre-amplifier of a comparator. The amplifiers may be abutted to one another such that an active transistor of a first differential stage in a first amplifier behaves as a dummy transistor for an adjacent differential stage in a second amplifier.
Abstract:
This invention eliminates the need for “capacitor coupling” or “transformer coupling,” and the associated undesirable parasitic capacitance and inductance associated with these coupling techniques when designing high frequency (˜60 GHz) circuits. At this frequency, the distance between two adjacent stages needs to be minimized. A resonant circuit in series with the power or ground leads is used to isolate a biasing signal from a high frequency signal. The introduction of this resonant circuit allows a first stage to be “directly coupled” to a next stage using a metallic trace. The “direct coupling” technique passes both the high frequency signal and the biasing voltage to the next stage. The “direct coupling” approach overcomes the large die area usage when compared to either the “AC coupling” or “transformer coupling” approach since neither capacitors nor transformers are required to transfer the high frequency signals between stages.
Abstract:
A portable unit with an endfire antenna and operating at 60 GHz makes an optimum communication channel with an endfire antenna in an array of antennas distributed over the area of a ceiling. The portable unit is pointed towards the ceiling and the system controlling the ceiling units selects and adjusts the positioning of an endfire antenna mounted on a 3-D adjustable rotatable unit. Several transceivers can be mounted together, offset from one another, to provide a wide coverage in both azimuth direction and elevation direction. These units can be rigidly mounted as an array in a ceiling, apparatus. The system controlling the ceiling array selects one of the transceivers in one of the units to make the optimum communication channel to the portable unit. The system includes the integration of power management features by switching between Wi-Fi in favor of the 60 GHz channel.
Abstract:
Processors are arranged in a pipeline structure to operate on multiple layers of data, each layer comprising multiple groups of data. An input to a memory is coupled to an output of the last processor in the pipeline, and the memory's output is coupled to an input of the first processor in the pipeline. Multiplexing and de-multiplexing operations are performed in the pipeline. For each group in each layer, a stored result read from the memory is applied to the first processor in the pipeline structure. A calculated result of the stored result is output at the last processor and stored in the memory. Once processing for the last group of data in a first layer is completed, the corresponding processor is configured to process data in a next layer before the pipeline finishes processing the first layer. The stored result obtained from the next layer comprises a calculated result produced from a layer previous to the first layer.
Abstract:
The differential output of a Programmable Gain Amplifier (PGA) is loaded by the input differential gate capacitance of a plurality of Analog to Digital convertors (ADC) comparators and the differential metal layer traces to interconnect these comparators to the PGA. The differential capacitive load presented to the PGA is quite large and reduces the bandwidth of this interconnect between the PGA and ADC. To overcome the performance degradation due to the differential capacitive load, an active negative-capacitor circuit cancels the effect of the large input capacitance of the ADC comparators. This cancelation extends the gain characteristics of the interconnect between the PGA's output and the inputs of the first stage of the comparators. The active negative-capacitance is comprised of a cross pair NMOS with a capacitor connecting their sources where each NMOS is biased by a current source.
Abstract:
A portable unit with an endfire antenna and operating at 60 GHz makes an optimum communication channel with an endfire antenna in an array of antennas distributed over the area of a ceiling. The portable unit is pointed towards the ceiling and the system controlling the ceiling units selects and adjusts the positioning of an endfire antenna mounted on a 3-D adjustable rotatable unit. Several transceivers can be mounted together, offset from one another, to provide a wide coverage in both azimuth direction and elevation direction. These units can be rigidly mounted as an array in a ceiling, apparatus. The system controlling the ceiling array selects one of the transceivers in one of the units to make the optimum communication channel to the portable unit. The system includes the integration of power management features by switching between Wi-Fi in favor of the 60 GHz channel.
Abstract:
In an up-converter path of a transmitter, wide-band signal system like direct. conversion WiGig, a high pass filter (HPF) is placed in the baseband path after the low pass filter (LPF) but before the mixers. The baseband signal of WiGig can have a bandwidth of 800 MHz. The HPF removes the frequencies from 0-40 MHz from the baseband signal and degrades the overall signal of the baseband by a dB or so. However, the frequency pulling is significantly reduced since oscillator frequency and Radio frequency (RF) transmitter frequencies after conversion become further separated when compared a system using to the conventional approach. This causes the injected signal to fall outside the locking range of the oscillator. The concern of substrate coupling is reduced and allows for a reduction in the physical distance between the oscillator and the mixer and reduces a shift in the desired target frequency of operation.
Abstract:
A cross coupled NMOS transistors providing a negative gm transistor feedback allows a mixer to saturate at a reduced input signal swing voltage when compared to a conventional mixer allowing the mixer to enter into the current mode operation at a reduced signal input voltage range. The linearity of the baseband signal path can be traded against the mixer gain and is improved if the signal swing in the baseband signal path is reduced. The input mixer transistors operate in the saturated mode at a reduced input signal swing voltage causing the power efficiency of the system to increase since the transmit chain operates at a class-D power efficient. Efficiency is very important in mobile applications to save and extend the battery power of a mobile phone providing a better utilization of the available power since most of that power is supplied to the energy of the outgoing modulated signal.