Abstract: The present disclosure describes a system that can include an antenna; a receive (Rx) path coupled to the antenna; and a transmit (Tx) path comprising a balun; and a radio frequency (RF) attenuator comprising a first port and a second port, the balun coupled to the first port, the antenna coupled to the second port. The RF attenuator can include a first switch coupled between the first port and the second port; a second switch and a first attenuator coupled to each other in series between the first port and the second port, the first attenuator having a first attenuator value; and a third switch and a second attenuator coupled to each other in series between the first port and the second port, the second attenuator having a second attenuator value greater than the first attenuator value of the first attenuator.

Abstract: Disclosed herein are related to systems and methods for correcting non-linearity due to duty cycle error. In one aspect, a system includes a mixer configured to up-convert transmission (Tx) data, a coefficient calibrator configured to select a target value of a coefficient based on a measurement of an interference signal due to non-linearity of the mixer, and an interference canceller coupled to the coefficient calibrator and the mixer. In some embodiments, the interference canceller is configured to generate compensated Tx data based on the Tx data and the selected target value of the coefficient and provide the compensated Tx data to the mixer. In some embodiments, the compensated Tx data corrects for the non-linearity of the mixer.

Abstract: Disclosed herein are related to systems and methods for correcting non-linearity due to duty cycle error. In one aspect, a system includes a mixer configured to up-convert transmission (Tx) data, a coefficient calibrator configured to select a target value of a coefficient based on a measurement of an interference signal due to non-linearity of the mixer, and an interference canceller coupled to the coefficient calibrator and the mixer. In some embodiments, the interference canceller is configured to generate compensated Tx data based on the Tx data and the selected target value of the coefficient and provide the compensated Tx data to the mixer. In some embodiments, the compensated Tx data corrects for the non-linearity of the mixer.

Abstract: Disclosed herein are related to systems and methods for selectively disabling current steering circuitries. In one aspect, the system includes a balun including a first inductor and a second inductor, a first current steering circuit coupled to the first inductor, a second current steering circuit coupled to the first inductor, and a controller coupled to the first current steering circuit and the second current steering circuit. In one aspect, the controller is configured to, based on input data having a first state, apply a first signal and a second signal having a first level to the first current steering circuit and a third signal and a fourth signal having the first level to the second current steering circuit to disable a first current through the second inductor, a second current through the first current steering circuit, and a third current through the second current steering circuit.

Abstract: Disclosed herein are related to systems and methods for correcting non-linearity due to duty cycle error. In one aspect, a system includes a mixer configured to up-convert transmission (Tx) data, a coefficient calibrator configured to select a target value of a coefficient based on a measurement of an interference signal due to non-linearity of the mixer, and an interference canceller coupled to the coefficient calibrator and the mixer. In some embodiments, the interference canceller is configured to generate compensated Tx data based on the Tx data and the selected target value of the coefficient and provide the compensated Tx data to the mixer. In some embodiments, the compensated Tx data corrects for the non-linearity of the mixer.

Abstract: Disclosed herein are related to systems and methods for selectively disabling current steering circuitries. In one aspect, the system includes a balun including a first inductor and a second inductor, a first current steering circuit coupled to the first inductor, a second current steering circuit coupled to the first inductor, and a controller coupled to the first current steering circuit and the second current steering circuit. In one aspect, the controller is configured to, based on input data having a first state, apply a first signal and a second signal having a first level to the first current steering circuit and a third signal and a fourth signal having the first level to the second current steering circuit to disable a first current through the second inductor, a second current through the first current steering circuit, and a third current through the second current steering circuit.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

Abstract: The disclosure is related to a method and a system for estimating a stock level of a shelf. An image processing technique is incorporated to conduct stock estimation that is used as a reference for replenishment decisions. In the method, a camera is used to capture a shelf image. The shelf image is divided into multiple sub-region images. Multiple binarized images with respect to the multiple sub-region images are obtained by applying a binarization method. A ratio of the binarization values with respect to the pixels within every sub-region is calculated. The method also includes comparing the ratio of the binarization values in at least two sub-regions with a reference ratio in the at least two sub-regions within a shelf reference image. The comparison is used to estimate the stock level, and also to determine whether the shelf is to be replenished.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

Abstract: The disclosure is related to a method and a system for estimating a stock level of a shelf. An image processing technique is incorporated to conduct stock estimation that is used as a reference for replenishment decisions. In the method, a camera is used to capture a shelf image. The shelf image is divided into multiple sub-region images. Multiple binarized images with respect to the multiple sub-region images are obtained by applying a binarization method. A ratio of the binarization values with respect to the pixels within every sub-region is calculated. The method also includes comparing the ratio of the binarization values in at least two sub-regions with a reference ratio in the at least two sub-regions within a shelf reference image. The comparison is used to estimate the stock level, and also to determine whether the shelf is to be replenished.

Abstract: Apparatus and methods for adjusting a gain of an electronic oscillator, such as a voltage-controlled oscillator (VCO), are disclosed. In one aspect, an apparatus for compensating for VCO gain variations includes a charge pump controller. The charge pump controller can be configured to select a VCO gain model based on a comparison of a VCO gain indicator and a threshold value stored in a memory, obtain VCO gain model parameters from the memory corresponding to the selected VCO gain model, and compute a charge pump current control value using the VCO gain model parameters. The charge pump current control value can be used to compensate for VCO gain variations.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.

Abstract: Apparatus and methods for adjusting a gain of an electronic oscillator, such as a voltage-controlled oscillator (VCO), are disclosed. In one aspect, an apparatus for compensating for VCO gain variations includes a charge pump controller. The charge pump controller can be configured to select a VCO gain model based on a comparison of a VCO gain indicator and a threshold value stored in a memory, obtain VCO gain model parameters from the memory corresponding to the selected VCO gain model, and compute a charge pump current control value using the VCO gain model parameters. The charge pump current control value can be used to compensate for VCO gain variations.

Abstract: Apparatus and methods for adjusting a gain of an electronic oscillator, such as a voltage-controlled oscillator (VCO), are disclosed. In one aspect, an apparatus for compensating for VCO gain variations includes a charge pump controller. The charge pump controller can be configured to select a VCO gain model based on a comparison of a VCO gain indicator and a threshold value stored in a memory, obtain VCO gain model parameters from the memory corresponding to the selected VCO gain model, and compute a charge pump current control value using the VCO gain model parameters. The charge pump current control value can be used to compensate for VCO gain variations.

Abstract: A dianhydride and a polyimide formed by the same are provided. The dianhydride has a chemical structure represented below: wherein Ar is a fluorene-containing group. The dianhydride can be polymerized with a diamine to form a polyimide with a repeating unit of a chemical formula: wherein Ar is the fluorene-containing group, and n is a positive integer from 1 to 5. The polyimide simultaneously has excellent thermal stability and hot workability, and can therefore be applied in several industries.

Abstract: A dianhydride and a polyimide formed by the same are provided. The dianhydride has a chemical structure represented below: wherein Ar is a fluorene-containing group. The dianhydride can be polymerized with a diamine to form a polyimide with a repeating unit of a chemical formula: wherein Ar is the fluorene-containing group, and n is a positive integer from 1 to 5. The polyimide simultaneously has excellent thermal stability and hot workability, and can therefore be applied in several industries.

Abstract: Apparatus and methods for adjusting a gain of an electronic oscillator, such as a voltage-controlled oscillator (VCO), are disclosed. In one aspect, an apparatus for compensating for VCO gain variations includes a charge pump controller. The charge pump controller can be configured to select a VCO gain model based on a comparison of a VCO gain indicator and a threshold value stored in a memory, obtain VCO gain model parameters from the memory corresponding to the selected VCO gain model, and compute a charge pump current control value using the VCO gain model parameters. The charge pump current control value can be used to compensate for VCO gain variations.

Abstract: A stacked synthesizer for wide local oscillator (LO) generation using a dynamic divider. The phase locked loop can include a plurality of voltage controlled oscillators (VCOs), and a selector that can be configured to select an output of one of the plurality of VCOs. The selected output of one of the plurality of VCOs can be provided to an on-chip dynamic divider and to an off-chip dynamic divider for LO sharing. The dynamic dividers can be configured to generate synthesizer outputs based on a multiplication of the selected output of one of the plurality of VCOs by a factor (1+1/M), where M is a variable number.