摘要:
A radio frequency receiver includes an amplifier and a detector that produces a bias control signal based on a signal environment. A bias level of the amplifier is set according to the bias control signal. Bias levels of other receiver circuits may have similarly adjusted bias levels, including buffers, IF oscillators, mixers, and converters. The invention can be used to increase range of linearity, intermodulation immunity and reduce power consumption by reducing the bias level under typical conditions and relying on the bias control to increase bias levels under adverse signal conditions. The invention has advantages where power is at a premium, particularly when a device is in standby mode, including mobile, portable and hand held pagers and wireless telephones and Internet connections. If standby mode operation in non-maximum signal environments dominates the usage of the receiver, then the invention can substantially increase battery life.
摘要:
A digital camera can employ logic to delay capturing a still image after a person has operated the control button until such time as predetermined subject criteria are met, e.g., the subject is smiling with eyes open, three or more players are in the field of view to ensure a good action shot, etc.
摘要:
A bypass circuit around a filter and RF amplifier of a front end device is activated when a received signal strength (RSS) passes a threshold in which the filter and RF amplifier are not necessary to filter/boost the received signal for processing in subsequent electronics (mixers, SAW filters, AGC amps, etc). A control device compares the RSS to the threshold and activates the bypass circuit. The bypass circuit is a switch coupled between an input of the filter and an output of the RF amplifier. The RF amplifier is shutdown when the bypass circuit is activated. The present invention may be used in combination with an LNA bypass to further decrease power consumption.
摘要:
A system for providing power to a wireless card includes power interface that provides power to a compact flash card. A boost regulator boosts the power from the power interface. A battery provides power that is summed with the power from the power interface. Moreover, a buck regulator limits the voltage of the summed power. A compact flash card can be powered by the power interface while a wireless card can be powered by the summed power.
摘要:
According to one embodiment of the invention, a compact wireless modem card placement in compliance with thickness requirement of type II PCMCIA standard and type II Compact Flash form factor standard is provided which includes a first side and a second side. The first side has a height clearance of approximately 2 mm. The second side, which is opposite the first side, has a height clearance of approximately 1.45 mm. In one embodiment, those components with a height greater than 1.4 mm are placed on the first side of the card. The first side of the card includes a radio-frequency transmitter (RFT) chip located at the lower left of the first side. The RFT chip performs signal processing functions to up-convert baseband signals received from a mobile station modem (MSM) chip to radio-frequency signals. The first side also includes a radio-frequency (RF) surface acoustic wave (SAW) filter located above and to the left of the RFT chip. The space between the RFT chip and the RF SAW filter is used to route the transmission line from each respective driver.
摘要:
A digital camera can employ logic to delay capturing a still image after a person has operated the control button until such time as predetermined subject criteria are met, e.g., the subject is smiling with eyes open, three or more players are in the field of view to ensure a good action shot, etc.
摘要:
The present embodiments provide apparatuses and methods for use in receiving radio frequency signals. In some embodiments, a method receives an input signal comprising data and jamming signals, amplifies the input signal according to a first adjustable bias level and producing a first internal signal. The first internal signal is mixed with an intermediate frequency signal to produce a second internal signal. The method detects a level of a signal that is proportional to a level of the input signal prior to baseband limiting filtering and as such is proportional to a level of the data and jamming signals. A bias control signal is generated that is dependent on the detected level of the detected signal, and the first bias level is adjusted according to the bias control signal. The bias control signal can increase as the level of the detected signal increases and can compensate for the jamming signals.
摘要:
A host device such as a camera, PDA, etc. can have an attachment such as a wireless modem, with both host and attachment having respective batteries. Some loads in the host are always powered by the host battery, and some loads in the attachment are always powered by the attachment battery, but some other loads in the attachment are selectively powered by either the host or attachment battery depending on a power consumption and/or the relationship between the charges remaining in the batteries.
摘要:
A first amplifier amplifies a radio frequency signal into a first stage signal, a detector produces a bypass signal based on the environment in which the receiver is operating. A switch provides the first stage signal or the first stage signal filtered by a radio frequency filter based on the bypass signal is not asserted. Optionally, the detector also produces a bias control signal and bias generators set the bias levels of the amplifiers according to the bias control signal. The invention increases linear range RF amplification stages. Power consumption is reduced by reducing the amplification (and optionally the bias levels) used under typical conditions. The invention is advantageous for applications where power is at a premium and the receiver, or at least its front end, operates while the device is in standby mode. Such applications include mobile, portable and hand held pagers and wireless telephones and Internet connections.