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 common-source Low Noise Amplifier (LNA) comprises a first spiral inductor coupled to a source of a first transistor, a second spiral inductor coupled to a drain of a second transistor, and a third inductor connecting the first transistor to the second transistor. The third inductor is configurable to enable a first capacitance to be coupled in parallel to form a bandpass filter. The first spiral inductor is configurable to enable a second capacitance to be coupled in parallel to form a resonant circuit. A variation of the LNA further includes a drain of a third transistor coupled to a gate of a fourth transistor with a first width, a source of the third transistor coupled to the resonant circuit, and an oscillator clock configured to operate at a first frequency that enables the third transistor, wherein the third transistor presents a first impedance to the resonant circuit, causing the resonant circuit to have a first bandwidth.
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 cascode amplifier circuit comprises a first spiral inductor coupled to a source of a first transistor; a second spiral inductor coupled to a drain of a second transistor; a third inductor connecting the first transistor to the second transistor; a first capacitor coupled in parallel to the third inductor forming a bandpass filter; and a second capacitor coupled in parallel to the second spiral inductor forming a resonant circuit, wherein the resonant circuit oscillates at a center frequency.
Abstract:
LO leakage and Image are common and undesirable effects in typical transmitters. Typically, thirty complex hardware and algorithms are used to calibrate and reduce these two impairments. A single transistor that draws essentially no de current and occupies a very small area, is used to detect the LO leakage and Image Rejection signals. The single transistor operating as a square law device, is used to mix the signals at the input and output ports of the power amplifier (PA). The mixed signal generated by the single transistor enables the simultaneous calibration of the LO leakage and Image Rejection.
Abstract:
The 60 GHz channel between the transmitter and receiver can have AWGN characteristics allowing a Time Domain Equalizer (TDE) to be used at the receiver instead of a Frequency Domain Equalizer (FDE). The complexity of performing matrix inversion on a received signal is reduced when directional antennas are used in a 60 GHz system. Incorporating the TDE in place of the FDE saves almost an order of magnitude in power dissipation. For portable units, such a savings is beneficial since the battery life can be extended. The signal quality of wireless channel is based on the characteristics of the received signal to switch the equalization operation from a system performing FDE to TDE and vice versa. The receiver adapts to the received signal to reduce the power dissipation of the system.
Abstract:
LO leakage and Image are common and undesirable effects in typical transmitters. Typically, thirty complex hardware and algorithms are used to calibrate and reduce these two impairments. A single transistor that draws essentially no de current and occupies a very small area, is used to detect the LO leakage and Image Rejection signals. The single transistor operating as a square law device, is used to mix the signals at the input and output ports of the power amplifier (PA). The mixed signal generated by the single transistor enables the simultaneous calibration of the LO leakage and Image Rejection.
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 large gain is used to start up the oscillation of the crystal quickly. Once the oscillation starts, the amplitude is detected. A control circuit determines based on the measured amplitude to disable a low resistance path in the controlled switch array to reduce the applied gain below the power dissipation specification of the crystal. Another technique introduces a mixed-signal controlled power supply multi-path resistive array which tailors the maximum current to the crystal. A successive approximation register converts the amplitude into several partitions and enables/disables one of several power routing paths to the inverter of the oscillator. This allows a better match between the crystal selected by the customer and the on-chip drive circuitry to power up the oscillator without stressing the crystal. The “l/f” noise of the oscillator circuit is minimized by operating transistors in the triode region instead of the linear region.