(b) two problems to be addressed in the use of power signal amplifiers: an efficient output of 2 high power output bands to compare: a resonance power amplifier with a high frequency small signal amplifier; a resonance power amplifier with a low frequency power amplifier; and 3. Similarities between a resonance power amplifier and a small signal amplifier; small signal amplifier wave graphs; validation amplifier wave graphs; common: both require high output power and high efficiency. The power amplifier is essentially an energy converter, which converts the direct flow energy supplied by the power to the communication energy, which is the efficiency of the power amplifier. The main technical indicators for power amplifiers are output power and efficiency;5, working state: the resonant power amplifier is usually used to magnify a narrowband high frequency signal and its working state is usually selected as a c working state (? C<90?), and its load must be a resonance route in order not to miss a true amplification signal. Non-coordination power amplifiers can be divided into low frequency amplifiers and broadband high frequency amplifiers. Low-frequency amplifier loads are unmodified and work in category a or b; broadband high-frequency amplifiers are carried by broadband transmission lines. Method of analysis of the resonance power amplifier: diagram, pyrolysis; 1, principle circuits; (a) the transfer properties curve is available according to the transistor: (i) the relation of the electro-voltage to currents in the resonance power amplifier; (ii) the relationship between the voltage and currents in the high-frequency power amplifier; lc backway energy conversion process; 4 , the power relationship and efficiency of the resonance power amplifier; two conclusions can be drawn from the above formula: how to reduce the total electro-depletion power at pc; and direct power:; so, the c-strength amplifier is more efficient? C by: 1, minus? C angles; and 2, allowing the lc to resonate on the base frequency of the signal, i. E. The maximum value of ic should be the minimum of vce. (b) in the non-linear resonance power amplifier, the working state of the amplification area is often divided into three categories depending on whether the condensation pole enters the saturation zone: ; when transistor characterization curves are idealized, the electrode current pulse in the c working state is a sharp cosine pulse. This applies to stress or critical states. (6); therefore, the values of vbm, vbb and vbz are known and the values of ? C are fully established. Reduction of formula (4) to formula (5), i. E. Ic = gcvbm (cos? T-cos? C) (7) when? T=0, ic = ic max, because? ? Ic max = gcvbm (1-cos 1? C) (8); if the tip-tip pulse is to be broken down to the number of the four leafs; the decomposition factor for the tip-tip pulse; the decomposition factor for the tip-tip pulse; 1. Dynamic properties of the resonance power amplifier; the working state of the high frequency amplifier is determined by four parameters: load resistance rp, incentive vb, power voltage vcc, vbb, etc. If the three parameters of vcc, vbb and vb remain unchanged, the working state of the amplifier is determined by the load resistance rp. At this point, the current, output voltage, power, efficiency, etc. Of the amplifier is known as the load of the amplifier. ; when the amplifier works in a state of condensation, its external circuit relationship is the following: (1) take point b in a straight line with a tilt of gd; (2) take points q and a and link them to a straight line. (b) 2. Load characteristics of power amplifiers; (ii) three working states of underpressure, overpressure, and criticality; based on the above analysis, it is possible to draw a load characterization curve for the condensation power amplifier; the advantage of an overpressure state is that when the load resists change, the output voltage is smoother and has a larger range, and when the pressure is weak, the efficiency is highest, but the output power is reduced, as is often the case for the intermediate and central band levels of the transmitter. ; the critical state is characterized by the highest output power and high efficiency, which is much less efficient than the maximum efficiency, and can be described as the optimal working state, which is often designed at the upper stage of the transmitter, as is often the case in the calculation of the tuning power amplifier. (a) 1. Adjustments to transport angles? C; 2. Adjustments to stress, criticality, hyperpressure working conditions; (i) changes rp, but no changes in vb, vcc, vbb, when the load resistance rp is small to large changes, the working state of the amplifier is moved from the criticality of pressure to the pressure. The highest output power at critical state. ; the effect of changes in vcc on the working state; the effect of changes in vcc on the working state; (3) changes in vbm, but changes in vcc, vbb, rp or vbb, but changes in the working status of amplifiers are the same in both cases. Because changes, whether vbm or vbb, result in vbe changes. ; the characteristics of the output voltage in the hyperpressure zone that vary with the changes made by the vic provide the basis for the realization of the total electrodes band; because changes to the banding process are used in the total electrodes circuit. Changes in working status and current and power levels in the vcc are shown above. ; vbm changes in current, power and power; example 4-1 harmonizing power amplifier output po has been detected and an increase in vbm has been introduced to enhance po when circuit parameters remain unchanged. However, the results were not clear, the reasons for the trial were analysed, and what measures could be used to achieve a significant increase in the po; the main indicator of the resonance power amplifiers was power and efficiency. In the case of criticality: 2); 0(? C), 1(? C), ..., ? N(c) can be measured and the actual value of a fraction obtained. (iv) based on; (ii) based on; (iv) for exchange voltage amplitude: vcm = vcc? = 24? 0. 9 = 21. 6 v relative power, efficiency. P=vcc? Ic0=24? 0. 506=12wpo=12; 4. 4. 1 general description; if the crossing angle is used to indicate the effect of the break time of the base area in the form of a dispersing condensation, due to the magnitude of the signal, the smaller condensed condensation is linear. In the case of large signal hf operations, the non-linear characteristics must be considered. ; at the high frequency of the operation, the movement of electrode currents in the power discharge tube at ? 0=10? 20?; (iii) gep ib: due to the reverse pulse of ie, according to ib=ie-ic, ib also has a reverse current pulse with its maximum value ahead of the maximum value of vbe, it can be seen that its base-wave weight is increasing and that the increase in ib1 will increase the incentive power than before vbe. ; when the frequency rises, it has been demonstrated that the gbor ib1 is rapidly increasing, indicating a significant reduction in communication resistance between b?-e, so that the impact of rbb? Is relatively higher and the required incentive power will be greater, which will further reduce power gain. ; 4. 4. 4. Saturation pressure down vces; when working at higher frequencies, consideration is given to the effects of the electrodes of the tubes, which are most affected by the telekinesis of the launching poles, as it enables parasitic coupling between input circuits. The general length of 10 mm leads is approximately 10-3? H and, at a working frequency of 300 mhz, the sense of resistance is about 1. 9? The negative feedback voltage of about 1. 9 v is generated by a high frequency 1a current. This negative feedback will certainly reduce output power and its gain and increase incentives. ; 4. 4. 1 direct-flow feed circuits; 1. Collective-teeth feed circuits; (i) serial feed circuits refer to a direct-flow feed circuit between the direct-flow source, the vcc, the load circuit (compatible network), and the power pipe. C1 and lc are low-access filter circuits, and point a is a high frequency (hf) ground level that both prevents the high frequency components in the power source vcc from influencing the amplifier work and avoids unnecessary loss of hf signals beyond the lc load circuit. The selection principle for c1, lc is? Lc > 10 ? Backway resistance 1 / ? C1 < 1/10 ? Backway resistance; basic principles for the composition of feeder lines; the external circuit equation must be satisfied, both in the form of collusion and in the form of feedback: (3) the advantages and disadvantages of the straight-flow circuits must be matched and given: in the feeder circuits, both end of the signal circuits are at a straight current, i. E. Zero. For hf, the end of the circuit is connected directly to the site, which makes it easier to install the circuit, so that the condensing cap c is free of high pressure and safe and reliable; shortcomings: in the feed-in circuit, the lc is at a high hf level, and its distribution to the ground is large, which will directly affect the stability of the circuit resonance frequency; the characteristics of the circuit are the opposite of that of the feeder。b. 2. Base-polar feed circuits; 3. Feed lines entered back circuits; 3) self-absorption anti-opposition pressure in bias circuits; 1. Inter-stage coupling networks; for the intermediate level, the following measures should be taken: 2. Output matching network; 1) ? Form matching network; the figure below is one of the two forms of a ? Network (or t-type network). Figure r2 is for terminal (loading) resistance and r1 is for equivalent resistance from r2 to the left, so the connection is indicated by a dash. ; the most common output circuit is the composite output loop, as shown in the figure. ; can be seen: from the transistor collection pole to the right, the equivalent is a conjunctive resonance path, as shown in the figure. ; in order for the majority of the output power of the device to be delivered to a load of ras, it is hoped that re-reflective resistance r? Circuit loss will be used to resist r1; ql should be kept as small as possible from the point of view of the efficiency of circuit transmission. However, the ql value should be large enough to take into account the good effect of the return filter. From the point of view of both, ql values should not normally be less than 10. Among the high-power amplifiers, ql is also below 10. ; the effect of changes in m on the working state; reflective electrical resistance; pa - antenna power; case: 1. 160 mhz, 13w modulation power amplifier magnifiers, with a power gain of 9db, can be given on a load of 50? 13w power, as shown in the chart. ; amplifiers have a power gain of 7 db and can give 50? Load output of 25 w power, with electrical circuits as shown in the figure. (b) transistor-c type multi-frequency devices are frequently used in launch systems to obtain the required launch frequency. Reasons for the introduction of multifrequency: (1) reduce the frequency of the main vibrator in favour of frequency stabilization indicators. (2) in order to increase the stability of the frequency of the transmission signal, the main vibrator is often a quartz crystal oscillator, but limited to the process, it is currently only possible to achieve tens of mhz, which is required to obtain a higher frequency signal. (3) increased frequency or interchange of fm transmitter signals, i. E. Deepening of the modem system. (4) the input and output frequencies of the multi-frequency vehicle are different and can therefore weaken the chain of forward and backward parasitic couplings, which are beneficial to the transmitter's stabilization. (5) widewidth amplifiers often take three forms: one, multiplication of multipliers; two, c, multiplication of amplifiers; and three, multiplications of parameters, which are multiplications achieved using the non-linear properties of transistor capacitors that vary with voltage. (c) type c multipliers work in category c, as the c amplifiers' total electrode ic is a pulsive wave form, and the current contains base and high-intensity frequencies for input signals. The output loops can be harmonized at a certain wave, so that a certain wave can be magnified. How do you choose the size of the channel angle? This is determined by the frequency of the multi-frequencyer, which is shown by the cosine pulsation coefficient, where the maximum value of the secondary domicular coefficient corresponds to the channel angle? C = 60, and the maximum value of the three domiciliary coefficients corresponds to the guide angle of about 40?, and when the frequency is higher, the channel angle is smaller. Should a multi-frequencyer work under pressure, critical or overpressure? Work is generally under pressure and critical. ; 4. 6. 3 leaching of load circuits; i; mastering the effects, characteristics and points of convergence and differences with the hf small signal amplifiers and low frequency power amplification. 1. Harmonisation power amplifiers are primarily used to magnify high frequency signals, which are designed to obtain useful signals for high power and efficient output. 2. The condensation power amplifier is characterized by an extremely negative bias of the transistor matrix, i. E., working in a working state of type c, with a combined electrode current of a cosine pulse, and an output voltage of a full sine wave due to a load of lc circuits. C. Distinctions and similarities between the tuning power amplifiers and the small signal tuning amplifiers; ; changes in polar voltages also cause changes in working conditions. The highest output power and efficiency during critical work, with low pressure and overpressure working conditions being used mainly for banding circuits. Overpressure working conditions are also used for intermediate magnification. (d) in order to improve efficiency, reduction of piped catheters and guaranteed load-back circuit resonance vi, acquisition of feed circuits and composite output networks, a full power amplifier consisting of power discharge tubes, feed circuits and resistance to matching circuits. Resisting matching circuits is the guarantee that the discharge tube collects electrodes, load resistance and enters to resist the required circuits. After the discharge tube, the amplifier is primarily designed to feed circuits and resist matching circuits. 7. Many of the effects of the hf operation are demonstrated by the hf operation, so there are some errors in the theoretical analysis and actual parameters, the distribution of electrical resistance, sensory and capacitation effects are not negligible, and the actual operational status of the pv is subject to experimental adjustments。
