CXG1400XR,CXG1405XR |
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■ Low pass-through loss, high linearity
Pass-through characteristics:
0.30 dB @900 MHz,
0.2 dB @13.56 MHz (RF-GND6)
Harmonic characteristics:
2fo: 72 dBc @900 MHz,
3fo: 66 dBc @900 MHz (RF-GND6)
■ Built-in high Q, high-precision
capacitors: Capacitor tolerance:
within ±7%.
■ Miniature, low-profile package:
2.3 mm × 2.3 mm × 0.35 mm(CXG1400XR)
2.0 mm × 2.0 mm × 0.35 mm(CXG1405XR)
■ Logic signal control of antenna tuning
Adjustment from 1 to 31 pF in 1 pF steps
(CXG1400XR)
Adjustment from 1 to 7 pF in 1 pF steps
(CXG1405XR)*³
*3: This device also supports adjustment
from 0.5 to 7.5 pF in 0.5 pF steps.
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 Low Pass-Through Loss, High Linearity |
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The Sony CXG1400XR and CXG1405XR
switching blocks are fabricated in Sony's
unique JPHEMT process, to achieve low
pass-through loss. (See table 1.)
Since the switching block is seen as a pass-though
loss when a capacitor is selected,
the capacitor's Q value will influence the loss. Therefore, achieving a high Q value in
the capacitor is effective for achieving a low
pass-through loss.
Another issue here is that “FeliCa” adopts a
modulation technique that uses comparatively
high voltage amplitudes. These products use
Sony's high linearity technology developed for
cellular phone antenna switches, and achieve
excellent communication characteristics even
when used in “FeliCa” applications. |
| Built-in High Q, High-Precision Capacitors |
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Sony’s MIMC* technology is used for the
built-in capacitors. By using thick-film plating
layering technology on a GaAs substrate,
Sony achieved high-precision capacitor with
high Q values. Also, since all the capacitors
in each path have the same sample-to-sample
variation characteristics, they are appropriate
for adjustment using bit control. (See table 1.)
* MIMC: Metal-Insulator-Metal Capacitor |
Miniature, Low-Profile Package
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The CXG1400XR is provided in a XQFN
miniature, low-profile package. (See figure
2a.) This results in a significantly reduced
mounting area compared to using external
capacitors, since the capacitors are integrated
in the package. (See figure 2b.)
The CXG1405XR adopts an even more
miniaturized package with a size of 2.0 × 2.0
mm. (See figure 2a.) |
Logic Signal Control of Antenna Tuning
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Figure 3 presents an example of practical
“FeliCa” antenna impedance matching.
The CXG1400XR and CXG1405XR adopt
a control method that differs from ordinary
antenna switches. In particular, CTL pins are
allocated to each path. This allows the creation
of a synthesized capacitance to optimize the
antenna impedance. (See figure 4.)
The CXG1400XR allows the capacitance to be
adjusted over a 1 to 31 pF range in 1 pF steps,
and the CXG1405XR allows the capacitance
to be adjusted in 0.5 pF steps. (See table 2.) |
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•••• Mr. Ikeda ••••
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The newly-developed CXG1400XR
and CXG1405XR introduced here
are designed for the completely new
application of antenna tuning, and as
such, differ from earlier antenna switches.
The CXG1400XR was designed for
“FeliCa” antenna tuning and has already
been used in cellular phone products.
Of course, it can also be used for
applications other than “FeliCa”. We
are currently designing a wide variety
of other antenna tuning SSC products,
and I strongly recommend that anyone
interested in this area contact Sony for
more information. |
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See
all articles with figures and tables.  |
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Vol.57 |
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