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Qorvo 1800MHz Small Cell RF Card Hardware User’s Guide
Hardware User’s Guide
8 Appendix A
– Alternate Reverse Build Variant
The Qorvo Card is a 2-channel FDD system with duplexers and filters tuned for specific uplink (RX) and
downlink (TX) center frequencies. Both channels are identical in the production build.
Downlink means a signal transmitted
from
the
DAC of RFSoC
, through the TX signal chain of the
Qorvo card,
to
a user-equipment radio receiver
LTE-band 3 calls for downlink max bandwidth ~75 MHz, centered at 1842.5 MHz
Uplink means a signal received at the RX signal chain of the Qorvo card, through the
ADC of
RFSoC
,
from
a user-equipment radio transmitter
LTE-band 3 calls for uplink max bandwidth ~75 MHz, centered at 1747.5 MHz
In order to facilitate convenient functional testing and demos of the card without external test equipment,
the layout was made with
“Reverse Variant” provision to enable swapping uplink and downlink paths to
perform a loopback test.
Reverse Variant Component Modifications
Configuring the card as a “Reverse Variant” requires the following component modifications.
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1. Enable CH2 downlink at 1747.5 MHz by replacing bandpass filter TQQ0303 with TQQ302 at U23,
and replacing RF Circulator Isolator RFSL5504 with RFSL5408 at U33.
2. Enable CH2 uplink at 1842.5 MHz by replacing TQQ0302 with TQQ303 at U22 and U32.
3. Enable CH2 duplexer to receive at 1842.5 MHz and transmit at 1747.5 MHz by moving two
capacitors to swap connections to the pins of the QPQ1297 Band 3 BAW Duplexer at U34. See
Figure 25 and Figure 27.
The system-level concept is shown in Figure 23.
Figure 23
– Reverse “Loopback” Concept
2
Inquiries for factory-modified REVERSE variant Qorvo cards may be directed to your local Avnet FAE
