Abstract: A step attenuator with constant input capacitance and having good performance is disclosed. In an exemplary design, an apparatus includes a step attenuator having a constant input capacitance for different amounts of attenuation. The step attenuator receives an input signal, provides a variable amount of attenuation for the input signal, and provides an output signal. The step attenuator may include a plurality of attenuator sections coupled in series. Each attenuator section may include a plurality of capacitors and may have the constant input capacitance. At least one of the plurality of attenuator sections may be selected or unselected to obtain a selected amount of attenuation for the step attenuator. An attenuator section may provide a predetermined amount of attenuation or a variable amount of attenuation when selected. The apparatus may further include a power detector that receives and determines the power of the output signal from the step attenuator.

Abstract: A diplexer includes a substrate having a set of through substrate vias. The diplexer also includes a first set of traces on a first surface of the substrate. The first traces are coupled to the through substrate vias. The diplexer further includes a second set of traces on a second surface of the substrate that is opposite the first surface. The second traces are coupled to opposite ends of the set of through substrate vias. The through substrate vias and the traces also operate as a 3D inductor. The diplexer also includes a capacitor supported by the substrate.

Abstract: Certain aspects of the present disclosure propose a method and an apparatus for antenna tuning and transmit path selection in an RF system. A method may include antenna diversity path selection by (optionally) diagnosing damaged antennas, tuning antennas, and selecting an antenna with better performance. Embodiments can be used in wireless radio-frequency (RF) front-ends. Other aspects, embodiments, and features are also claimed and described.

Abstract: Systems and methods are provided for backing up database storage. A protection policy for database storage is activated at a remote host, wherein the database storage is not physically accessible by the computing device, such that the out-of-band storage is not in communication with the remote host through the computing device. A backup request is transmitted to the remote host comprising data indicative of a volume on the database storage to back up according to the protection policy. A response to the backup request is received comprising staging disk requirements including a required size for a staging disk. A staging disk is determined based on the response. The staging disk is presented to the remote host so that the remote host can perform a backup of the volume to the staging disk using a database backup tool provided by a vendor of the database storage.

Abstract: Techniques for controlling transmit power and adjusting an antenna tuning network of a wireless device are disclosed. In an exemplary design, an apparatus (e.g., a wireless device or a circuit module) includes a directional coupler and at least one detector. The directional coupler receives an input radio frequency (RF) signal at a first port, provides an output RF signal at a second port, and provides a coupled RF signal at a third port. The detector(s) receive at least one RF signal on at least one port of the directional coupler, measure the at least one RF signal, and provide measurements that are used to control the transmit power of the wireless device and adjust an antenna tuning network. For example, the measurements may be used to determine incident power, reflected power, delivered power, etc., which may be used to control the transmit power and/or adjust the antenna tuning network.

Abstract: Power detectors with temperature compensation and having improved accuracy over temperature are disclosed. In an aspect of the disclosure, variations of a power detector gain over temperature is reduced by varying both the gate and drain voltages of MOS transistors within a power detector. In an exemplary design, an apparatus includes at least one MOS transistor, which receives an input signal, detects the power of the input signal based on a power detection gain, and provides an output signal indicative of the power of the input signal. The at least one MOS transistor is applied a variable gate bias voltage and a variable drain bias voltage in order to reduce variations of the power detection gain over temperature. At least one additional MOS transistor may receive a second variable gate bias voltage and provide the variable drain bias voltage for the at least one MOS transistor.

Abstract: Certain aspects of the present disclosure propose a method and an apparatus for antenna tuning and transmit path selection in an RF system. A method may include antenna diversity path selection by (optionally) diagnosing damaged antennas, tuning antennas, and selecting an antenna with better performance. Embodiments can be used in wireless radio-frequency (RF) front-ends. Other aspects, embodiments, and features are also claimed and described.

Abstract: A wireless device configured for optimizing a delivered power is described. The wireless device includes a filter duplexer or switch coupled to a transmitter and a receiver. The wireless device also includes a power/impedance detector coupled to the filter duplexer or switch. The power/impedance detector includes a directional coupler. An antenna is coupled to the power/impedance detector. Other aspects, embodiments and features are also claimed and described.

Abstract: A multi-antenna station has multiple remote front-ends coupled to multiple antennas. Each remote front-end includes a power amplifier (PA), a low noise amplifier (LNA), and first and second coupling units. On the transmit path, a first RF signal is received via a first port, routed by the first coupling unit to the power amplifier, amplified to obtain the desired output power level, and routed by the second coupling unit to a second port for transmission via the antenna. On the receive path, a second RF signal is received via the second port, routed by the second coupling unit to the LNA, amplified to obtain a higher signal level, and routed by the first coupling unit to the first port for transmission to the transceiver.

Abstract: Techniques for adaptively tuning an impedance matching circuit are disclosed. In an aspect, the impedance matching circuit is pre-characterized. The performance of the impedance matching circuit is determined for multiple settings of the impedance matching circuit, stored in memory, and used to tune the impedance matching circuit. In another aspect, the impedance matching circuit is tuned based on measurements for one or more parameters such as delivered power, return loss, power amplifier current, antenna/load impedance, etc. In an exemplary design, an apparatus includes a memory and a control unit. The memory stores information for multiple settings of an impedance matching circuit. The control unit selects one of the multiple settings of the impedance matching circuit based on the information for the multiple settings and measurements for the impedance matching circuit. The impedance matching circuit performs impedance matching for a load circuit (e.g., an antenna) based on the selected setting.

Abstract: A system and method of providing driver software to a test controller to facilitate testing by a wireless transceiver tester of a device under test (DUT). Using the wireless transceiver tester, executable tester instructions are accessed from one or more computer readable media and in accordance therewith bi-directional signal communications are established between the wireless transceiver tester and the test controller, and between the wireless transceiver tester and the DUT. Further accessed are executable driver instructions, including a plurality of executable driver program instructions for driving at least one of the wireless transceiver tester and the DUT, which are communicated to the test controller.

Abstract: Reconfigurable impedance matching circuits with multiple configurations are disclosed. A reconfigurable impedance matching circuit may be implemented with a set of reactive elements (e.g., inductors and/or capacitors) and a set of switches. Different configurations may be obtained with different settings of the switches and may be associated with different impedance tuning curves. This may enable the reconfigurable impedance matching circuit to provide better impedance matching for a load circuit (e.g., an antenna). In an exemplary design, the reconfigurable impedance matching circuit includes at least one variable reactive element configured to tune the impedance of the reconfigurable impedance matching circuit in order to provide better impedance matching. In an exemplary design, the reconfigurable impedance matching circuit may include at least one reconfigurable reactive element, each of which can be connected as a series element or a shunt element.

Abstract: An amplified stepped gain mixer portion improves the signal-to-noise ratio of a receiver by using multiple gain states to improve linearity. The mixer portion includes an amplifier, a switch and two transistors. The amplifier output is coupled to the sources of the two transistors. An oscillating signal is present on the transistor gates. The transistor drains are coupled to one another through the switch when the switch is closed. The mixer portion operates in two modes. In a 1/2 mode, the mixer portion output current flows only through the first transistor and not through the second transistor because the switch is open. In a 2/2 mode, the mixer portion output current flows through both transistors. The mixer portion is configured such that the switch is closed when a switching signal is asserted. The switching signal is asserted when a bit of a mixer control register is written to.

Abstract: A system and method of providing driver software to a test controller to facilitate testing by a wireless transceiver tester of a device under test (DUT). Using the wireless transceiver tester, executable tester instructions are accessed from one or more computer readable media and in accordance therewith bi-directional signal communications are established between the wireless transceiver tester and the test controller, and between the wireless transceiver tester and the DUT. Further accessed are executable driver instructions, including a plurality of executable driver program instructions for driving at least one of the wireless transceiver tester and the DUT, which are communicated to the test controller.

Abstract: Certain aspects and embodiments provide for accurate measurement and estimation of imbalances between in-phase (I) and quadrature (Q) components of a complex baseband signal. The accuracy of I/Q phase imbalance estimates may be enhanced by conducting them on a transmitter and a receiver that are connected via a local, loopback connection and by removing cross-spectrum interference in transferred packets. Once these accurate I/Q phase imbalances are determined, they may be used to adjust a signal processed by the transmitter or the receiver to increase the performance and data throughput of communications using the signal.

Abstract: Techniques for performing inphase/quadrature (I/Q) imbalance estimation and compensation are described. In one exemplary design, I/Q imbalances in a receiver may be estimated by (i) applying a continuous wave signal at different frequencies to the receiver and (ii) processing I and Q input samples from the receiver to determine I/Q imbalances at different frequencies. In another exemplary design, I/Q imbalances may be estimated by (i) downconverting an input RF signal with an LO signal that is offset in frequency from the input RF signal, (ii) transforming I and Q input samples from the receiver to the frequency domain to obtain I and Q symbols, and (iii) determining I/Q imbalances based on the I and Q symbols. In one exemplary design, I/Q imbalances may be corrected by compensating for frequency-dependent and frequency-independent I/Q imbalances separately. I/Q imbalances in a transmitter may also be estimated and compensated.

Abstract: To meet a radiated power limit, a transmitting station determines a synthesized antenna pattern based on steering vectors used for spatial processing and estimates an array gain based on the synthesized antenna pattern. Different spatial processing modes (e.g., eigensteering and spatial spreading) result in different synthesized antenna patterns. The array gain may be estimated based on the spatial processing mode used for the data transmission and applicable parameters (e.g., eigenvalues) for that mode. An element gain for each antenna used for data transmission may also be estimated. The transmitting station then limits the transmit power for the data transmission based on the array gain, the element gain, and the radiated power limit, which may be an effective isotropic radiated power (EIRP) limit imposed by a regulatory agency.

Abstract: To meet a radiated power limit, a transmitting station determines a synthesized antenna pattern based on steering vectors used for spatial processing and estimates an array gain based on the synthesized antenna pattern. Different spatial processing modes (e.g., eigensteering and spatial spreading) result in different synthesized antenna patterns. The array gain may be estimated based on the spatial processing mode used for the data transmission and applicable parameters (e.g., eigenvalues) for that mode. An element gain for each antenna used for data transmission may also be estimated. The transmitting station then limits the transmit power for the data transmission based on the array gain, the element gain, and the radiated power limit, which may be an effective isotropic radiated power (EIRP) limit imposed by a regulatory agency.

Abstract: An amplified stepped gain mixer portion improves the signal-to-noise ratio of a receiver by using multiple gain states to improve linearity. The mixer portion includes an amplifier, a switch and two transistors. The amplifier output is coupled to the sources of the two transistors. An oscillating signal is present on the transistor gates. The transistor drains are coupled to one another through the switch when the switch is closed. The mixer portion operates in two modes. In a 1/2 mode, the mixer portion output current flows only through the first transistor and not through the second transistor because the switch is open. In a 2/2 mode, the mixer portion output current flows through both transistors. The mixer portion is configured such that the switch is closed when a switching signal is asserted. The switching signal is asserted when a bit of a mixer control register is written to.

Abstract: Certain aspects and embodiments provide for accurate measurement and estimation of imbalances between in-phase (I) and quadrature (Q) components of a complex baseband signal. The accuracy of I/Q phase imbalance estimates may be enhanced by conducting them on a transmitter and a receiver that are connected via a local, loopback connection and by removing cross-spectrum interference in transferred packets. Once these accurate I/Q phase imbalances are determined, they may be used to adjust a signal processed by the transmitter or the receiver to increase the performance and data throughput of communications using the signal.