The Q1000

The first Quantance product is the Q1000 PA Power Controller.  Available in a compact monolithic CSP package, the tiny Q1000 can be seamlessly integrated with common radio frequency PA transmit circuits and requires minimal connections, no special software or firmware, and no special calibration, leaving the original RF transmit circuit architecture virtually unchanged.

Applications

The Q1000 is intended for use with PAs commonly used in WCDMA/HSDPA/HSUPA cell phones, PDAs, smart phones, data cards, laptops, and other wireless mobile products. 

Frequency Band

The Q1000 is tested and validated specifically for 3GPP Band I and II operation.

Product Technology

The Q1000 operates the PA of an RF transmit circuit in saturation mode to optimize the efficiency of the PA while at the same time maintaining RF signal linearity and saving battery life by using closed loop feedback to drive the supply voltage level at the PA to track the RF signal modulation envelope in real time to operate the PA in saturation mode.  This quickly changing PA input voltage is produced by an efficient, low noise, ultra fast power converter that is integral to Q1000.  In close coordination with the ultra fast power converter, signals from the RF output of the PA are fed back to RF correction circuitry within the Q1000 to eliminate distortions to ensure the RF signal output from the PA is linear. For a more detailed description, please refer to the TECHNOLOGY section.

Roadmap

Quantance is already developing other product implementations to address tri-band (3GPP Band I, II, V) and quad-band operation (Band I, II, V, VI).

Product Integration

The Q1000 does not change the primary architecture of a phone or data card design.  Control signals that were previously used to control the PA can be used to control the Q1000, which in turn controls the PA.  The battery supply connection that was previously made to the PA can be used unchanged to connect to the Q1000, which then provides a modulated supply voltage to the PA.  The input from the RF transceiver previously connected to the PA can be connected unchanged to the input of the Q1000, which then passes a corrected signal into the PA.

Software control

No special software or firmware is needed to include the Q1000 in common transmit circuits. A simple suite of initial commands from the primary base band processor SPI port is all that is needed to automatically configure the Q1000 for operation within your circuit.

Low Voltage Operation

The Q1000 is operational to a battery voltage input as low as 2.7VDC. This enables the Q1000 to maintain its functionality over an extended battery voltage range, common to circuits driven by batteries that are almost depleted. This also means the Q1000 is already capable of supporting the next generation of smaller, low voltage batteries.

Specification Summary

Package type: compact monolithic 36 ball CSP package

Package size: 2.48mm x 2.43mm x .66mm (mounted height)

Input voltage: 2.7VDC – 5VDC

Q1000 Performance

When using the Q1000 in an RF transmit circuit with a common PA, the RF power output can be increased significantly without increasing battery current when compared to the same circuit without the Q1000. Similarly, using the Q1000, a PA can produce the same power output with signicantly less battery power. At peak power, the Q1000 brings an additional benefit. It is fairly common that at peak power a PA needs to be operated with a reduction of power called "back-off" in order to meet 3GPP signal linearity specifications when amplifying signals with high peak to average ratios (PAR), which is common in HSDPA and HSUPA. In these cases, the PA may not be able to reach its power output maximum since this back-off can be 2dB or more. However, with the Q1000, the PA can be operated without back-off to achieve the maximum power output specified by 3GPP. So in addition to the significant current savings that the Q1000 provides at peak power, it also can enable a PA to operate without back-off, enabling an additional 2dB of peak power that otherwise would not be available.

In cases where the ambient temperature is high and the RF transmit circuit of a wireless mobile device must output high power, the PA of the transmit circuit may cross a thermal threshold and thus be restricted on the maximum output power it can produce. When the same PA transmit circuit utilizes the Q1000, the junction temperature of the PA can be reduced signifcantly at the RF power output peak, dropping the PA operation well below the thermal limit and thus enabling the PA to operate with more power over a wider temperature range. Even if the PA does not approach the thermal limit, the temperature savings that the Q1000 enables can reduce the heat significantly, providing a more pleasant user experience and helping to improve overall product reliability.

The battery current and junction temperature reductions outline above are provided for a smart phone architecture. RF transmit circuits for cell phones, data cards, embedded data modules and other mobile wireless products have similar transmit circuits, but designs vary by application and manufacturer. Similar trends in savings can be expected for these devices, but total savings will vary.

For more specific performance information, please contact quantance at info@quantance.com.

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