Abstract: A synchronous prescaler is provided that has an input line for receiving an input signal, which is synchronized to a low order dual modulus prescaler. The dual modulus prescaler generally divides responsive to a mode command line, but may have a dead-zone period where it may fail to respond to a generated mode command. The dual modulus prescaler also has an output line that is synchronized to an extender section. The extender section is used to further divide the input signal, and is synchronized to an adjustable counter section. A sync controller circuit receives an output from the counter section, as well as a timing signal from the extender, and generates the mode signal on the mode command line. In this arrangement, the sync controller generates the mode signal at a time when the low order dual modulus is in a condition to change divide modes, thereby avoiding providing the signal during the dead-zone period.

Abstract: A transmitter for a wireless handset having a modified translation loop architecture. The transmitter includes a VCO that generates a modulated transmit signal having a frequency fTx, and a modulated signal source that generates a modulated LO signal with a frequency fLO. A mixer mixes the transmit signal with the LO signal to produce an IF signal having a frequency fIF. A first divider divides the LO signal frequency fLO by an integer M to generate a first comparison signal having a frequency fCF. A second divider divides the IF signal frequency fIF, after it is multiplied by an integer K, by an integer N to generate a second comparison signal having a frequency fCF. The transmit and LO signal frequencies have the relationship f Tx = f LO ? KM ± N M . A phase detector coupled to the first and second comparison signals compares the phases of the signals and outputs a control voltage to the VCO proportional to any phase differences between the signals.

Abstract: The tone generator uses a highly accurate frequency signal to generate an accurate and stable tone signal. A cadence pattern may be used to output the tone signal onto a test cable in an easily distinguishable pattern. The tone signal may be selectively output at an in-band band frequency or an out-band frequency. A corresponding tone probe may be used to detect the tone signal. The tone probe uses a high-Q bandpass filter to reject all but the expected frequency of the tone signal. The signal passing the bandpass filter is proportional to the detected tone signal. The tone probe generates an audio signal unrelated to the frequency of the tone signal. The audio signal is modulated by the signal from the bandpass filter, and then broadcast through a speaker. Accordingly, the tone probe provides an audible sound proportional to the strength of the tone signal, but is unrelated in frequency.

Abstract: The modular switch instrument card has a single or double slot card frame having a front panel. The card frame has module receiving areas for receiving selected switch modules. Each switch module is configured to provide a particular switching function. One or more switch modules may be positioned into the module receiving areas such that switch connectors on the switch modules extend through the front panel and are available for connection to an automated test system. The switch modules may be fixedly mounted within the card frame or may be removably coupled. Each switch module couples to an interconnect bus backplane enabling all installed switch modulars to communicate to a switch interface. The switch interface provides a communication interface to the VXI backplane, thereby providing a uniform and consistent programming interface independent of which switch modules are presently installed into the module receiving areas.