Changes between Version 6 and Version 7 of Internal/NoiseGenerator/Hardware/WiBo
- Timestamp:
- Jan 14, 2007, 3:43:28 AM (18 years ago)
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Internal/NoiseGenerator/Hardware/WiBo
v6 v7 3 3 !WiBo is a RF front-end board for Orbit Noise Generator designed around a Maxim, Inc. MAX2829ETN+D radio transceiver chip. Schematic is [attachment:WiBi-103-Schematics.pdf attached]. It is manufactured as a 4.00 x 4.00” printed circuit board (PCB). 4 4 5 === MAX2829ETN+D Transciever WLAN chip(U1) ===5 === MAX2829ETN+D Transciever (U1) === 6 6 7 The MAX2829 is a complex multifunction radio transceiver chip that incorporates most of the radio functions except for the reference oscillator, baseband I/Q amps, power amps and antenna switches. Please refer to the [at achement:MAX2828-9ds.pdf data sheet] and eval board notes for more information (also check http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4532). Chip configuration is done by !BiBo over the serial bus through the programming pins:7 The MAX2829 is a complex multifunction radio transceiver chip that incorporates most of the radio functions except for the reference oscillator, baseband I/Q amps, power amps and antenna switches. Please refer to the [attachement:MAX2828-9ds.pdf data sheet] and eval board notes for more information (also check http://www.maxim-ic.com/quick_view2.cfm/qv_pk/4532). Chip configuration is done by !BiBo over the serial bus: 8 8 9 9 ||!BiBo function||!WiBo function||MAX2829 function|| … … 16 16 === RF Control Register (U2) === 17 17 18 U2 (74HC595), an 8bit serial in parallel out shift register (http://www.fairchildsemi.com/ds/MM/MM74HC595.pdf). Register programming programming is done with:18 [attachment:MM74HC595.pdf 74HC595] is an 8bit serial in parallel out shift register used to provide control signals for various RF functions. Register programming signals: 19 19 20 20 ||!BiBo function||WiBo102 function||74HC595 function|| … … 23 23 ||RADIO_IO 4||U2 SER||Serial Data In|| 24 24 25 25 This register controls five functions, namely, turn on/off of the 2GHz and 5GHz power amps, MAX2829 transmit and receive control signals and the MAX2829 shutdown. The register bit assignment is given in the following table: 26 26 27 27 ||01234567||Function|| … … 40 40 Note: 0 is the first bit in, so shift in reverse order 41 41 42 === LT C 1994 Baseband amps (U3xx, U4xx) ===42 === LT1994 Baseband Amplifiers (U3xx, U4xx) === 43 43 44 U300, U320 are high speed differential opamps ( LTC1994) wired in a 2nd order Butterworth filter with cutoff of 10MHz. They act as reconstruction filters for the output of the AD9862 DACs, which are current mode differential outputs of 0-20mA. These amps also DC offset their output to 1.1 VDC to optimally match the MAX2829 inputs.44 U300, U320 are high speed differential opamps ([attachment:lt1994.pdf LT1994]) wired in a 2nd order Butterworth filter with cutoff of 10MHz. They act as reconstruction filters for the output of the AD9862 DACs, which are current mode differential outputs of 0-20mA. These amps also DC offset their output to 1.1 VDC to optimally match the MAX2829 inputs. 45 45 These amps are enabled only when TXENA is high, thereby saving about 18mA of power. 46 46 47 U400, U420 are buffer amps (gain=1) for the MAX2829 baseband I/Q signal outputs (which have 60k ohm output impedance). These amps provide simple 1st order RC filtering with cutoff F = 6 MHz. U400,U420 DC offset to 2.0VDC before sending the baseband I/Q signals to BiBo’s AD9860. These amps are enabled only when RXENA is high.47 U400, U420 are buffer amps (gain=1) for the MAX2829 baseband I/Q signal outputs (which have 60k ohm output impedance). These amps provide simple 1st order RC filtering with cutoff F = 6 MHz. U400,U420 DC offset to 2.0VDC before sending the baseband I/Q signals to !BiBo’s AD9860. These amps are enabled only when RXENA is high. 48 48 49 49 === uPG2035 Switches (U3, U4, U5) === 50 50 51 U3,U4 and U5 make up a switching matrix which offers several antenna diversity options. 52 These are fast switching low-loss DPDT switches. 51 U3,U4 and U5 make up a switching matrix which offers several antenna diversity options. These are [attachment:uPG2035.pdf fast switching low-loss DPDT switches]. 53 52 54 53 U5 is the TX output switch which switches 2.4 and 5.6 GHz MAX2829 outputs between two antennas A03 and A04. When LED3 is lit (power up default), the switch is “crossed” so the MAX2829 2.4 GHz output is routed to antenna A03 and 5.6 GHz is routed to A04. … … 56 55 U4 is the RX input switch which switches antennas A01 and A02 to both the 2.4 and 5.6 GHz MAX2829 inputs. When LED1 is lit (power up default), the switch is “crossed” so MAX2829 2.4 GHz input is routed to antenna A02 and 5.6 GHz is routed to A01. 57 56 58 The default design does not incorporate U3. Some soldering and jumpering is required to bring U3 into the mix which enables single antenna operation or maximum spatial antenna seperation (using A01 and A04). No further notes are given here.57 The default design does not incorporate U3. Some soldering and jumpering is required to bring U3 into the mix which enables single antenna operation or maximum spatial antenna seperation (using A01 and A04). 59 58 60 59 === AWL6951 Power amp (U6) === 61 60 62 The AWL6951is a dual mode (2.4 and 5.6GHz RF power amp) with enable signals and log detectors for measuring power output. U2 control signals 2G PA and 5G PA should only be enabled one-at-a-time to prevent overheating the chip. AUX_ADC_B1 and AUX_ADC_B2 measure the log detector outputs of the 2G and 5G amps respectively. The following measurements were taken,61 The [attachment:AWL6951.pdf AWL6951] is a dual mode (2.4 and 5.6GHz RF power amp) with enable signals and log detectors for measuring power output. U2 control signals 2G PA and 5G PA should only be enabled one-at-a-time to prevent overheating the chip. AUX_ADC_B1 and AUX_ADC_B2 measure the log detector outputs of the 2G and 5G amps respectively. The following measurements were taken, 63 62 64 63 * Pout (2.4GHz) @ 210 mA = 20.5 dBm (right on spec) Vout(logDET) = 0.727 V 65 64 66 * Pout(5.3GHz) @ 220 mA = 19.0 dBm (right on spec) Vout(logDET) = oops?65 * Pout(5.3GHz) @ 220 mA = 19.0 dBm (right on spec) Vout(logDET) = ? 67 66 68 * Pout(5.9GHz) @ 220 mA = 15.0 dBm (-3 dB off spec) Vout(logDET) = oops?67 * Pout(5.9GHz) @ 220 mA = 15.0 dBm (-3 dB off spec) Vout(logDET) = ? 69 68 70 69 Current draw is that of just the power amp and RF power measured at output of SMA connector when 100kHz modulation is transmitted. Otherwise MAX2829 and other circuitry draws about 170mA so total is about 480-500 mA. … … 91 90 For orientation purposes, reference marks are shown along the top (A-D) and right sides (1-4) of the board in one inch increments. 92 91 92 [[Image(WiBo103-Photo.jpg) !WiBo PCB]] 93 93 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). 94 94 A trace width of 30 mils and gap-to-ground of 18 mils provides a very close match to a 50ohm characteristic impedance.
