6?10解：R1?Rp?XC1?C1?XR1QL12?fXC1?R2R1L1?XL1Vcm2P014410?2?VCC2P02?2422?2?144?????14.4???1?221?pF2?3.14?50?10??1??116.956?14.4200?R2L1?Q2L2001446?16.95?????100?1??12?f?2?3.14?50?10?0.054??H?XC2?C2?QLR1?R2?2QL?1??QLX1?L1?10?144?200??1???1???2.57????100?1?10?16.95??162?fXC22?3.14?50?10?2.57?1239?pF?2cm?1?RP增加一倍，放大器工作6?11解：?2?RP减小一半，放大器工作6?12解：?k?r?r1?r?Vcm2P02于过压状态，于欠压状态，?11?1Q1Q2k2Vcm变化不大，P0??V2
/2RP?0.5P0；Icm变化不大，P0??IcmRP/2?2P0。?2
?1?111?1100?15?0.032?L1?L2Q1Q2??M?VCE?sat??2P0RPQL182?57.4%?26?13解：RP???V
CC??12?0.5?2?1?66???设QL?10C1?12?fXC1?则XC1??6610?6.6????241?pF502?3.14?10?6.6?L??5.5???XC2?RL?1?Q?R2LRP?11?1?10??502866?1C2?X12?fXC2?2?3.14?10?5.5?290?pF?L1?XQLRP?RL?1?2QL?1?QLXC2?L1?10?66???102?1??19.9?nH50??1????12.5???10?5.5??L1?2?f?12.52?3.14?108?
?a?将R1C1和R2C2串联电路改为6?14证：R1??XC1R1?XC12222?C1?和R?R1C?并联电路，并设22R211?QL2XC1?XC1R1QL?2?XCR2222R1??R2XC2R2?XC2XC12222?1?XCR1?R1222R1?XC1XC2222R2?XC2XC2?，即R1??匹配时R1??R2?XC2?R2R1?XC12R1?R2?XC2R2?1?Q?R2L2R121?1R122C12XL1?1?XC?2??XC?R1222R?XXC1??R22222C2R?X?XC2?11?QL2R1?XC1XC1?XC1R1?XC122R1R2XC2R1QL1?QL2?R1R2XC2R1QL?R2??1?21?QL?QLXC2?R1QL??XL1R222?????b?将R1C1和R2L1串联电路改为R1??XC1R1?XC1222?C1?和R??并联电路，并设R1L12XL12XC1?XC1R1??R2R2?XL1XC122C122R211?Q2L?1?XCR1?R1222R1?XC1XL1R?X222L12R2?XL12XL1?，即R1??匹配时R1??R2?XL1?R2R?X21R1?R2?1?Q?R2L2R1?1R22222L1?1?XC?1?XC2?XL?XC1R1?XC1222R?X?XL1??R12122C1R?X?XC1?R1QL1?QL2?R1R2XL1R1QL1?QL2R1QL1?QL2R2QLXL1??R1QL?R2???12??1?QL?QLXL1??1?天线断开，工作于过压6?18解：?2?天线接地，工作于欠压?3?中介回路失谐，工作于?1?PA?P??PC?Pk?106?19解：?2??k?3??c??PAP??PCP??PCP???610?310?310状态，集电极直流电表状态，集电极直流电表欠压状态，集电极直流?3?1?6?W读数减小，天线电流表读数略增，天线电流表电表读数略增，天线电读数为0；读数增加；流表读数减小。??85.7%?70%??PAP??610?60%
6?20解：当k?kc时，?k?1???1?若?kr1r1?r??r1r1?r??50%则r??r11Q1Q2?kc?1Q01Q?3Q?3kc?90%则r???9r1故k?Q09
6?25解：
6?27解：??o2?60????60o1?，?P0减小，工作于欠压状态V6?28解：RVi?I?933I?9RL 6?29解：Vbm?VBZ?VBB0.6cos???1.45cos70o?6?V?VB?Vbm?VBB?6?1.45?4.55?V?iB?VBZ4.55?0.6Cmax?V2?2?1.98?A?Iocm1?iCmax?1?70??1.98?0.436?0.86?A?Vcm?VCC?gcriCmax?24?1.98?22.02?V?PIcm1Vcm.86?22.010?2?02?9.47?W?P?QL?A???1??P??10?0??1??9.47?8?Q?.52?W?0??100? 6?30解：VVBZ?VBB0.6?1.5bm?cos??cos70o?6.14?V?VB?Vbm?VBB?6.14?1.5?4.64?V?iVB?VBZ4.64?0.6Cmax?2?2?2.02?A?Iocm1?iCmax?1?70??2.02?0.436?0.88?A?Vcm??VCC?0.9?24?21.6?V?PIcm1Vcm.88?21.60?2?02?9.5?W?P?QL?A???1??P?10?0??1???9.5?8.?Q?8?W?0??100?
。
?a?电路可能振荡，属于电7?5解：感反馈式振荡电路；?e?电路可能振荡，属于电容反馈式振荡电路；?h?电路可能振荡，属于电容反馈式振荡电路；?b?、?c?、?d?电路不可能振荡；?f?电路在L2C2?L3C3时有可能振荡，属于电容反馈式振荡电路?g?电路计及Cbe可能振荡，属于电容反馈式振荡电路。?1?有可能振荡，属于电容7?6解：反馈式振荡电路，f1?f2?f0?f3；?2?有可能振荡，属于电感反馈式振荡电路，f1?f2?f0?f3；?4?有可能振荡；属于电容反馈式振荡电路，f1?f2?f0?f3；?3??5??6?不可能。
7?7解：
?1?f0?7?21解：?2?gd?12π1RPL?C?Cd?1Q6??2?3.14?13?101?7??20?5??10?5.27?mS?12?100?MHz?CL??20?5??1010?7?12?
?3?0.06~0.08V?1?fq?7?26解：1.657?10d?5?Sd1.657?100.4?21.1?100.436?4.14?MHz?5??Cq?21.1?10Lq?43.5d3?2000.4?0.105?pFS?43.5?dS?2200?14?mH??21.2?Ω??19.8?pFrd?42500B?42500?0.25?Sd?3.96?101.050.254?20.42002000.4C0?3.96?10Qq?1.05Bfq???10d?64?10?0.4?168006?2?d?1.657?10?1.657?1015?106?0.11?mm?
?1?1.5~1.5001?MHz7?27解：?负阻特性。
、高稳定度克拉泼振荡电路。
?2?不能?3?不能，普通三极管没有7?28解：恒温槽、稳压电源电路、共集电极缓冲级等。
7?29解：并联c?b型（皮尔斯）晶体振荡
9?3解：i?I?1?macosΩt?cosω0t?Icosω0t?I22macos?ω0?Ω?t?2I2macos?ω0?Ω?t2I有效值??I??I??I?ma???ma??????2??22??22?I21?ma22?
?1?v?25?1?0.7cos2π5000t?0.3cos2π10000t?sin2π106t9?4解：?25sin2π10t?8.75?sin2π1005000?sin2π9950006??3.75?sin2π1010000?sin2π990000??2?包络25?1?0.7cos2π5000t?0.3cos2π10000t?m上?m下?Vmax?V0V0V0?VminV0??25??1?0.7?0.3??252525?25?1?0.7?0.3?25?0.4峰值调幅度谷值调幅度?1
14?100?25?W12?1?ma?1时9?5解：?2?ma?0.3时3P?ω0?Ω??P?ω0?Ω??14maP0T?1422??
P?ω0?Ω??P?ω0?Ω??maP0T?9?6解：i?b1v?b3v不包含平方项，不能产4生调幅作用。
?0.3?100?2.25?W?1?P?ω0?Ω??P?ω0?Ω??9?7解：P0avηP0Tη14maP0T?214?0.7?5000?612.5?W2?P?ω0?Ω??2P?ω0?Ω??1225?W???2?P????50000.5?10?kW?3?P??P0avη?1?ma?1时9?8解：22??ma?0.7?P0T?5000???1?2???1?2?????????12.45?kW?η0.5
P?ω0?Ω??P?ω0?Ω??14maP0T?214?1000?250?W??P0?P0T?P?ω0?Ω??P?ω0?Ω??1000?250?250?1500?W?2?ma?0.7时14maP0T?2P?ω0?Ω??P?ω0?Ω??14?0.7?1000?122.5?W2??
P0?P0T?P?ω0?Ω??P?ω0?Ω??1000?122.5?122.5?1245?W9?9解：f?f0?f1?f2?f3?f4?5?20?200?1780?8000?10005?kHz?