QHX220 Datasheet, PDF (1/19 Pages) Intersil Corporation – Active Isolation Enhancer and Interference Canceller

Active Isolation Enhancer and Interference Canceller
QHx220
Features
Electromagnetic Interference (EMI) is emerging as a
major concern in next generation wireless
communication systems. As wireless terminals now
support multiple services and features that utilize high
data rates simultaneously, removing interference within
wireless terminals like handsets has become a challenge.
Reducing the Electromagnetic Interference recovers
the receiver sensitivity, enabling simultaneous
operation of multiple radios, and improves the overall
quality of service of communication devices. Intersil’s
QHx220 is situated in a handset to sample the source
of the noise and emulate the RF coupling channel
between the noise source and victim receiver antenna.
In doing so, an anti-noise signal can be applied directly
to the victim receive path to cancel the EMI and
achieve the signal integrity benefits. This approach
makes it possible to cancel both in-band (within the
victim Rx band) or out-of-band aggressors. This is a
revolutionary approach since it is only possible to
cancel out of band noise using conventional Rx filters.
In addition QHx220 may be used to increase the
inherent isolation between antennas or inside duplexers
and switches, thus allowing to increase the transmit
power in repeaters or yielding higher sensitivity in the
receivers. Both measures finally resulting in a better
coverage, larger cell size, smaller antennas or lower
power of infrastructure components such as
basestations, pico-and Femtocells as well as repeaters.
The QHx220 integrates the sampler path LNA gain stages
as well as the DACs required to control the I and Q
control voltages (used to set the magnitude and phase of
the cancellation signal). Both the gain, and control
voltages are programmable using a SPI bus interface.
• Protocol agnostic. Designed for: GSM, CDMA, DVB-H,
ISDB-T, DMB
• Frequency Range 300MHz to 3GHz
• Integrated, programmable LNA gain stages in the
sampler path
• SPI bus controlled integrated DACs
• >20dB Noise Cancellation is possible
• 50dB typical Dynamic Range
• Low Power Consumption (<20mW typical, ~2µW
standby)
• Ultra Small ~ 1mm² devices are available as tested
bumped die or 3x3mm² QFN package
Applications
• Most any wireless device with a local aggressor:
- Cell phones
- Mobile TV devices
- Laptop Computers
- GPS terminals
- Pico- and Femtocells
• Improved Tx to Rx Isolation of devices (i.e. duplexer,
switches) or between neighboring antennae
• Basestations
• Linearization of PAs
Typical Application Circuit
Benefits
• Actively cancels unwanted local RF noise
• Improves BER, receiver sensitivity, C/N by canceling
noise generated from local aggressors
• Improves isolation between adjacent antennas
• Can be used to cancel in-band or out-of-band
interferers (i.e. spurs, harmonics, phase noise, or
other noise sources like IM products generated in a
PA)
• Enables simultaneous operation of multiple
co-located radios
• Improves overall quality of service
FIGURE 1. ACTIVE ISOLATION ENHANCER AND NOISE
CANCELLER
October 20, 2009
FN6986.0
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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