Abstract:
An integrated duplexer based on electrical balance is described. The duplexer module includes a hybrid transformer. The hybrid transformer includes a primary coil and a secondary coil. The primary coil is coupled between an output of a power amplifier and an antenna. The secondary coil is coupled between an input of a low noise amplifier and ground. The duplexer also includes a balancing impedance that is coupled between the primary coil and the secondary coil.
Abstract:
Exemplary embodiments are directed to providing electrostatic discharge (ESD) protection of a cascode device of an amplifier. In an exemplary embodiment, a transistor is configured to receive a bias voltage and at least one circuit element coupled to the transistor and configured to receive an input voltage via an input pad. Additionally at least one diode can be coupled to a drain of the first transistor and configured to limit a voltage potential at an internal node of the amplifier caused by the input pad.
Abstract:
Techniques for improving performance of a transformer shared amongst a plurality of operating modes. In an aspect, first and second primary windings of a transformer are coupled to an AC ground voltage. Primary windings are mutually coupled to a secondary winding of the transformer. To render the second primary winding inactive, e.g., when operating in a first mode, a switch coupling the second primary winding to the common reference voltage is opened. Similarly, when it is desired to render the first primary winding inactive, e.g., when operating in a second mode, a switch coupling the first primary winding to the common reference voltage is opened. In this manner, the inactive primary winding advantageously does not load the secondary winding. Further aspects provide for, e.g., extending the techniques to more than two modes, and alternative techniques to mutually couple the signal from the primary to the secondary winding.
Abstract:
A wireless communication device configured for reducing Tx leakage in a receive signal is described. The wireless communication device includes a transceiver chip. The transceiver chip includes a receiver, a feedback receiver and a transmitter. The wireless communication device also includes a Tx leakage signal reduction module. The Tx leakage signal reduction module reuses the feedback receiver.
Abstract:
Power supply rejection in a single-ended receiver, through impedance balancing, is described. The single-ended receiver includes a first low noise amplifier and a second low noise amplifier. The single-ended receiver also includes a multi-port coupled transformer that outputs a differential signal. The multi-port coupled transformer includes a first primary coil that is coupled to an output of the first low noise amplifier and a second primary coil. The single-ended receiver also includes balancing impedances at the output of each of the low noise amplifiers. These impedances can be configured such that the on impedance of the first low noise amplifier equals the combined impedance of the off impedance of the second low noise amplifier and the balancing impedance. This balancing of impedances on the first and second primary coils results in power supply rejection of noise and spurious signals.
Abstract:
An integrated duplexer based on electrical balance is described. The duplexer module includes a hybrid transformer. The hybrid transformer includes a primary coil and a secondary coil. The primary coil is coupled between an output of a power amplifier and an antenna. The secondary coil is coupled between an input of a low noise amplifier and ground. The duplexer also includes a balancing impedance that is coupled between the primary coil and the secondary coil.
Abstract:
Amplifiers with shunt switches to mitigate interference are disclosed. In an exemplary design, an apparatus includes an amplifier and a shunt switch. The amplifier has an input operatively coupled to an input/output (I/O) pad of an integrated circuit (IC) chip. The shunt switch grounds the amplifier when the shunt switch is closed. The shunt switch is isolated from the I/O pad and the amplifier input. The amplifier may be a low noise amplifier (LNA) or some other type of amplifier. In an exemplary design, the shunt switch is isolated from the I/O pad by a series switch. The series switch and the shunt switch may be closed when the amplifier is disabled and may be opened when the amplifier is enabled.
Abstract:
A single-ended receiver is described. The single-ended receiver includes a multi-port transformer that outputs a differential signal. The multi-port transformer includes a first primary coil that is coupled to an output of a first low noise amplifier. The multi-port transformer also includes a second primary coil that is coupled to an output of a second low noise amplifier. The multi-port transformer further includes a first secondary coil. The single-ended receiver also includes a shared mixer that receives the differential signal from the multi-port transformer.