wiki:Internal/NoiseGenerator/Hardware/WiBo

Version 3 (modified by (none), 18 years ago) ( diff )

Orbit Noise Generator Wireless Board (WiBo)

WiBo102 is a 4.00 x 4.00” printed circuit board (PCB) designed around a Maxim, Inc. MAX2829ETN+D radio transceiver chip. This chip incorporates most of the radio functions except for the reference oscillator, baseband I/Q amps, power amps and antenna switches.

Four antennas (A01-A04) are mounted directly to WiBo102 though provision is made for adding SMA connectors and using off-board antennas if necessary. Two antennas are primarily for transmission (Tx) and two for receiving (Rx). Antenna switching is possible for diversity gain. It is also possible to switch all Tx and Rx signals into a single antenna.

  1. PCB

The PCB is a 4.00 x 4.00” FR-4 four-layer controlled impedance stackup board manufactured by Advanced Circuits, Inc.(http://www.4pcb.com/index.htm). For orientation purposes, reference marks are shown along the top (A-D) and right sides (1-4) of the board in one inch increments.

Looking from the top down, the top copper layer is the component side with all the high-frequency RF transmission lines. The dielectric under this layer is 20 mils thick. The structure of the traces is coplanar waveguide with ground (CPWG). A trace width of 30 mils and gap-to-ground of 18 mils provides a very close match to a 50ohm characteristic impedance.

The next copper layer down is all ground plane. The third layer down is a signal layer with predominately vertical traces surrounded by ground plane. The fourth or bottom layer is another signal layer with predominately horizontal traces.

BiBo’s ADC (analog-to-digital conversion) and DAC (digital-to-analog) conversion comes from an Analog Devices AD9860 MxFE processor. Digital RADIO_IO_x signals come from a Xilinx Spartan 3.

RADIO_IO_1/¾ download programming coefficients to the MAX2829.

RADIO_IO_3/4 are shared with U2 (74HC595), an 8bit serial in parallel out shift register. http://www.fairchildsemi.com/ds/MM/MM74HC595.pdf U2 in turn controls five functions, namely, turn on/off of the 2GHz and 5GHz power amps, MAX2829 RXENA and TXENA signals and the MAX2829 shutdown (/SHDN). Meaning of control signals

Assuming the MAX2829 has already been programmed, to enable a TX RF output the user must program a 11001xxx into U2.

NOTE! Do not turn on both the 2GHz and the 5GHz power amps at the same time! ALSO! Do not turn on both the RXENA and TXENA lines (not sure why?).

Connector J3_F and I/O

This is a 40-pin 2mm dual-inline connector which mates BiBo’s control signals, +3.3 VDC power and ground to WiBo102.

WiBo102 functionJ3_F functionpin#pin#J3_F functionWiBo102 function
hi-speed MAX2829 TXBBQ-DACB-213.3VA
hi-speed MAX2829 TXBBQ+DACB+43GND
hi-speed MAX2829 TXBBI-DACA+653.3VA
hi-speed MAX2829 TXBBI+DACA-87GND
phase modulation of U23AUX_DAC_C1093.3VA
ref osc VCXO frequency adjustAUX_DAC_B1211GND
PLL speed up monitorAUX_DAC_A14133.3VA
½ supply voltageAUX_ADC_A1115 GND
RSSI from MAX2829AUX_ADC_A2 1817N/C
2GHz power amp detectorAUX_ADC_B120193.3VD
5GHz power amp detectorAUX_ADC_B22221GND
hi-speed MAX2829 RXI+ADCA+24233.3VD
hi-speed MAX2829 RXI-ADCA_2625GND
hi-speed MAX2829 RXQ+ADCB+28273.3VD
hi-speed MAX2829 RXQ-ADCB-3029GND
MAX2829 /CSRADIO_IO 132313.3VD
U2 RCKRADIO_IO 23433GND
MAX2829 SCLK and U2 SCKRADIO_IO 33635RADIO_IO 8MAX2829 LD (lock=1=LED on)
MAX2829 DIN and U2 SERRADIO_IO 43837RADIO_IO 7U5 switch(straight=0,cross=1)
U3 switch(straight=0,cross=1)RADIO_IO 54039RADIO_IO 6U4 switch(straight=0,cross=1)

Control Register U2

Note: A is the first bit in, so shift in reverse order

012345678Function
1xxxxxxxxturn MAX2829 on (/SHDN)
x1xxxxxxxturn MAX2829 TX on (TXENA)
xx1xxxxxxturn MAX2829 RX on (RXENA)
xxx1xxxxx5G PA: 5GHZ power amp on
xxxx1xxxx2G PA: 2GHz power amp on
xxxxx1xxxSPARE 1 output on
xxxxxx1xxSPARE 2 output on
xxxxxxx1xSPARE 3 output on
xxxxxxxx1SPARE 4 output on, 9th bit

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