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RX BLOCKFig 1-1 Rx block Although Rx part circuit design base on 50ohm,but also need matching circuit,instead of connect directly.Because of the impedance is not 50ohm for all frequency in one cell circuit.Therefore,one cell circuit connect another cell the cascaded response might be much different than we anticipate,especially at the out of band area.Respectively,Fig 1-2Fig 1-4 is BPF1,LNA,BPF2 Schematic,and Fig 1-5 is BPF1+LNA+BPF2 united schematic.SCHEMATIC OF BPF1Fig 1-2 BPF1 schematicSCHEMATIC OF LNAFig 1-3 LNA schematicSCHEMATIC OF BPF2Fig 1-4 BPF2 schematicBPF1+LNA+BPF2Fig 1-5 BPF1+LNA+BPF2 schematicUnite 47nH and 33nH inductors to 82nHModify 15pF to 12pF,in order to improve IP3MATCHINGCompare the united circuit with each cell circuit,we only change one capacitance C419:15pF12pF,in order to improve H channel IP3.There is 5 samples unite circuit test data as follow:S-PARAMETER TEST DATA L CHANNEL(136MHZ)Fig 1-6 BPF1+LNA+BPF2 L channel TestS-PARAMETER TEST DATA L CHANNEL(136MHZ)Fig 1-7 BPF1+LNA+BPF2 L channel TestAt least Gain is 13dB for sensitivityS-PARAMETER TEST DATA L CHANNEL(136MHZ)Fig 1-8 BPF1+LNA+BPF2 L channel Isolation TestAt least IsolationS-PARAMETER TEST DATA L CHANNELS-PARAMETER TEST DATA L CHANNEL(136MHZ)S-PARAMETER TEST DATA M CHANNEL(155MHZ)Fig 1-9 BPF1+LNA+BPF2 M channel TestS-PARAMETER TEST DATA M CHANNEL(155MHZ)At least Gain is 13dB for sensitivityS-PARAMETER TEST DATA M CHANNEL(155MHZ)Fig 1-10 BPF1+LNA+BPF2 M channel Isolation TestAt least IsolationS-PARAMETER TEST DATA M CHANNEL(155MHZ)S-PARAMETER TEST DATA M CHANNEL(155MHZ)S-PARAMETER TEST DATA H CHANNEL(174MHZ)Fig 1-11 BPF1+LNA+BPF2 H channel TestS-PARAMETER TEST DATA H CHANNEL(174MHZ)At least Gain is 13dB for sensitivityS-PARAMETER TEST DATA M CHANNEL(155MHZ)Fig 1-12 BPF1+LNA+BPF2 H channel Isolation TestAt least IsolationS-PARAMETER TEST DATA H CHANNEL(174MHZ)S-PARAMETER TEST DATA H CHANNEL(174MHZ)H Channel dB(S(2,2)is not well,due to the resonance L606/C615.RX SYSTEM REJECTIONRejection/dBLo isolationIFAB21AB22AB11AB12AB13AB14AB15FrequencyMHzL180.8544.85112.85158.425225.7406.55587.4768.25949.1M199.8544.85122.35177.425244.7444.55644.4844.25954.4H218.8544.85131.85196.425263.7482.55701.4920.251049.4LPFL00002030303030M00003330303030H00004230303030BPF1L10251052310201010M10251052010201010H10251051610201010BPF2L20351574520302030M20351573720302030H20351573020302030TotalL506025128860806070M506025128860806070H506025128860806070At least50552088550755065Table 1-1 Rx system rejectionIncluding LNA isolation(20dB)According to Table 1-1 Rx spurious frequency rejection,we need to provide more attention on the rejection of AB21,AB22,AB11,because their filter protection play a big role in rejecting this spurious frequencies from going into the mixer.Measured BPF1+LNA+BPF2 rejection as table 1-2:Rejection/dBLo IsolationIFAB21AB22AB11AB12AB13AB14AB15FrequencyMHzL180.8544.85112.85158.425225.7406.55587.4768.25949.1M199.8544.85122.35177.425244.7444.55644.4844.25954.4H218.8544.85131.85196.425263.7482.55701.4920.251049.4Targeted Rejection for Spurious Frequencies L508025106860606060M508025105260606060H508025104360606060BPF1+LNA+BPF2 Test data For 5 smaples(min)L70953421.571.996939090M6610332.921.35595979291H6510732.815.64489899091At Least Request in RX System CircuitsL50552086520452035M50552085220452035H50552084320452035Table 1-2A BPF1+LNA+BPF2 Test rejectionBPF1+LNA+BPF2 REJECTIONRejection/dBGainLo IsolationIFAB21AB22AB11AB12AB13AB14AB15FrequencyMHzL136180.8544.85112.85158.425225.7406.55587.4768.25949.1M155199.8544.85122.35177.425244.7444.55644.4844.25954.4H174218.8544.85131.85196.425263.7482.55701.4920.251049.4BPF1+LNA+BPF2 Sample 1#L13.3172.4995352673.3103939091M14.5466.9112332455.11009710192H1567.110732.6318.7346.8989899598BPF1+LNA+BPF2 Sample 2#L13.4371.3910334.223.376.3107939193M14.5667.210334.422.6955.6989996100H14.8968.2107.533.8916.4844.39929895100BPF1+LNA+BPF2 Sample 3#L13.5570.831023524.472.597989891M14.8567.110232.923.956.01011049293H15.566.8115.832.818.2445.01891069290BPF1+LNA+BPF2 Sample 4#L13.3570.7610038.121.574.1969310890M14.6866.110536.1821.3555.4495999491H15.166.211035.5815.6644.61901009092BPF1+LNA+BPF2 Sample 5#L13.6871.4810338.422.171.9112969688M14.8166.310636.122.256.1969710394H15.365.4108.235.5716.1845.0790959593Targeted Rejection for Spurious FrequenciesL13508025106860606060M13508025105260606060H13508025104360606060Table 1-2B BPF1+LNA+BPF2 Test rejectionAs shown from Table 1-2 BPF1+LNA+BPF2 Test rejection,the redundancy of AB22(H channel),AB11(L,M,H channel)is the most little.Therefore,we may take care of their rejection when optimize circuit parameter.IP3 TESTBPF1+LNA+BPF2 IP3 EstimationdBmOP3GainIP3L12.4813.03-0.54M13.0114.24-1.23H12.5515.19-2.64Base on each cell circuit IP3,estimation BPF1+LNA+BPF2 unite circuit IP3 as shown left table.The test data as follow:IP3 TESTTable 1-3BPF1+LNA+BPF2 IP3 TestAs shown from Table 1-3,IP3 test data of BPF1+LNA+BPF2 is 1dB(at least)better than estimation.The worst IP3 is H channel BPF1+LNA+BPF2,is-1.87dB(at least).According Rx system IM estimation,IP3 for BPF1+LNA+BPF2 is least-3dBm to ensure Rx system IM to reach 66dB(CE).CONCLUSIONSBPF1+LNA+BPF2 measured performance meets design goal.One thing to note is the rejection for Image frequency may need to improve if LPF rejection at Image Frequency is insufficient.LNA output matching circuit should be optimized based on the input impedance of the input impedance of the next stage.Therefore,during circuit optimization,the value for L406,C419,C417 need to be re-optimize.A matching circuit between BPF2 output and Mixer input is requisite.
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