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:
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:
Herein is presented, a low power on-die 60 GHz distribution network for a beamforming system that can be scaled as the number of transmitters increases. The transmission line based power splitters and quadrature hybrids whose size would be proportional to a quarter wavelength (˜600 μm) if formed using transmission lines are instead constructed by inductors/capacitors and reduce the area by more than 80%. An input in-phase I clock and an input quadrature Q clock are combined into a single composite clock waveform locking the phase relation between the in-phase I clock and quadrature Q clock. The composite clock is transferred over a single transmission line formed using a Co-planar Waveguide (CPW) coupling the source and destination locations over the surface of a die. Once the individuals the in-phase I and quadrature Q clocks are required, they can be generated at the destination from the composite clock waveform.
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.
Abstract:
A phase lock loop (PLL) is an important component in wireless systems. CMOS technology offers voltage controlled oscillator designs operating at 60 GHz. One of the difficulties is dividing the high frequency clock down to a manageable clock frequency using conventional CMOS. Although injection locked dividers can divide down this clock frequency, these dividers have limitations. A divide by 2 is presented that uses several techniques; feed forward, clock amplification and series peaked inductors to overcome these limitations.
Abstract:
Herein is presented, a low power on-die 60 GHz distribution network for a beamforming system that can be scaled as the number of transmitters increases. The transmission line based power splitters and quadrature hybrids whose size would be proportional to a quarter wavelength (˜600 μm) if formed using transmission lines are instead constructed by inductors/capacitors and reduce the area by more than 80%. An input in-phase I clock and an input quadrature Q clock are combined into a single composite clock waveform locking the phase relation between the in-phase I clock and quadrature Q clock. The composite clock is transferred over a single transmission line formed using a Co-planar Waveguide (CPW) coupling the source and destination locations over the surface of a die. Once the individuals the in-phase I and quadrature Q clocks are required, they can be generated at the destination from the composite clock waveform.
Abstract:
Sallen-Key filters require an operational amplifier with a large input impedance and a small output impedance to meet the external filter characteristics. This invention eliminates the need for internal feedback path for stability and increases the gain of a source follower which has characteristics matching the operational amplifier in the Sallen-Key filter. The source follower provides 6 dB of AC voltage gain and is substituted for the operational amplifier in the Sallen-Key filter. The Sallen-Key filter requires a differential configuration to generate all the required signals with their compliments and uses these signals in a feed forward path. Furthermore, since the source follower uses only two n-channel stacked devices, the headroom voltage is maximized to several hundred millivolts for a 1.2V voltage supply in a 40 nm CMOS technology. Thus, the required 880 MHz bandwidth of the Sallen-Key filter can be easily met using the innovative source follower.
Abstract:
Capacitive adjustment in an RCL resonant circuit is typically performed by adjusting a DC voltage being applied to one side of the capacitor. One side of the capacitor is usually connected to either the output node or the gate of a regenerative circuit in an RCL resonant circuit. The capacitance loading the resonant circuit becomes a function of the DC voltage and the AC sinusoidal signal generated by the resonant circuit. By capacitively coupling both nodes of the capacitor, a DC voltage can control the value of the capacitor over the full swing of the output waveform. In addition, instead of the RCL resonant circuit driving a single differential function loading the outputs, each output drives an independent single ended function; thereby providing two simultaneous operations being determined in place of the one differential function.
Abstract:
Capacitive adjustment in an RCL resonant circuit is typically performed by adjusting a DC voltage being applied to one side of the capacitor. One side of the capacitor is usually connected to either the output node or the gate of a regenerative circuit in an RCL resonant circuit. The capacitance loading the resonant circuit becomes a function of the DC voltage and the AC sinusoidal signal generated by the resonant circuit. By capacitively coupling both nodes of the capacitor, a DC voltage can control the value of the capacitor over the full swing of the output waveform. In addition, instead of the RCL resonant circuit driving a single differential function loading the outputs, each output drives an independent single ended function; thereby providing two simultaneous operations being determined in place of the one differential function.