RF5300_1 Datasheet, PDF (5/10 Pages) RF Micro Devices – 3V, 5GHz LINEAR POWER AMPLIFIER

RF5300
Theory of Operation
The RF5300 is a three-stage device with a nominal gain of 28dB to 30dB in the 4.9GHz to 5.850GHz ISM band. The RF5300
is designed primarily for IEEE802.11a/n WLAN applications where the available supply voltage and current are limited. This
amplifier will operate to (and below) the lowest expected voltage made available by a typical PCMCIA slot in a laptop PC, and
will maintain required linearity at decreased supply voltages.
The RF5300 requires only a single positive supply of 3.0V nominal (or greater) to operate to full specifications. Power control is
provided through two bias control input pins (VREG1, VREG2, and VREG3), but in most applications these are tied together and
used as a single control input.
There is no external matching required on the input and output of the part, thus allowing minimal bill of material (BOM) parts
count in end applications. Both the input and the output of the device are DC-blocked.
For best results, the PA circuit layout from the evaluation board should be copied as closely as possible, particularly the ground
layout and ground vias. Other configurations may also work, but the design process is much easier and quicker if the layout is
copied from the RF5300 evaluation board. Gerber files of our designs are available on request.
The RF5300 is not a difficult part to implement, but care in circuit layout and component selection is always advisable when
designing circuits to operate at 5GHz.
It is important to isolate VCC1 from other RF and low-frequency bypass capacitors on this supply line. This can be accom-
plished using a suitably-long transmission line which is RF shorted on the other end as described above. Ideally the length of
this line will be a quarter wavelength, but it only needs to be long enough so that the effects of other supply bypass capacitors
on the VCC1 line are minimized. If board space is a concern, this isolation can also be accomplished with an RF choke inductor
or ferrite bead.
The RF5300 has primarily been characterized with a voltage on VREG1, VREG2, and VREG3 of 2.8V_DC. However, the RF5300
will operate from a wide range of control voltages. If you prefer to use a control voltage that is significantly different than
2.8V_DC, contact RFMD Sales or Applications Engineering for additional data and guidance.
Rev A9 DS070820
7628 Thorndike Road, Greensboro, NC 27409-9421 · For sales or technical
support, contact RFMD at ([phone] or [e-mail].
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