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DuNE™ Antenna Tuning Technology
DuNE Technology for Mobile TV
Mobile TV applications such as DVB-H and ISDB-T also require very broadband reception and delivering good coverage to an already complex system, all in a small space. Achieving broadband reception is directly related to the physical size of the antenna and the handset; any antenna mismatch degrades range and reception quality. To date, designers have typically had only two antenna choices: a passive internal antenna with poor performance, or
the external whip antenna. The embedded, internal antenna is demanded by the market, yet poor performance is not accepted. As a result, interest in “tunable” internal antennas – those which cover a narrow section of the bandwidth and can be “retuned” as the receive channel changes – is increasing.
When the DVB-H antenna is embedded in the GSM handset, the tunable element for DVB-H antenna tuning needs to be able to handle high levels of coupled GSM power without shift in capacitance or causing nonlinearities. Typically better than +26dBm of linear power handling is required to meet GSM/DVB-H interoperability requirements. The existing design options for mobile TV antenna tuning (such as varactor diodes or bulk-CMOS switched capacitor banks) do not meet these power handling requirements. Using a high-linearity switch (e.g. SP4T) to implement switchable tuning network can meet interoperability requirements, but results in very rough tuning.
The first devices in the DuNE DTC portfolio are designed to meet the stringent broadband requirements for DVB-H and ISDB-T mobile TV; multi-mode, multi-band GSM/WCDMA cellular handsets; and the power handling requirements for interoperability between the two applications.
Peregrine’s new DuNE DTCs for mobile TV have been designed for 5 bits of resolution or 32 tuning states, which provides the level of fine resolution that is required to tune the antenna across the entire mobile TV band. As well, DuNE Technology enables a Q = 40–70 at 470 to 862 MHz for a 1.36 to 6.3pF (4.6:1) tunable capacitor. The current consumption is only 11 µA at +2.75 V, while meeting the stringent power handling requirements of better than +28dBm and IIP3 > +62dBm.
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