Philips Semiconductors Military Linear Products Ce eee e rere reer eee eee rece ees Wideband high frequency amplifier FEATURES GOOMHz bandwidth 20dB insertion gain 4.8dB (6dB) noise figure Zp = 75Q (Zq = 509} No externa! components required Input and output impedances matched to 50/75Q systems APPLICATIONS Antenna amplifiers Amplified splitters Signal generators Frequency counters Oscilloscopes Signal analyzers Broadband LANs @ Fiber optics Modems @ Mobile radio Telecommunications DESCRIPTION The 5205 is a high-frequency amplifier with a fixed insertion gain of 20dB. The gain is flat to +0.5dB from DC to 450MHz, and the -3dB bandwidth is greater than GOOMHz. The 5205 Operates with a single supply of 6V, and only draws 33mA of supply current which is much less than comparable hybrid parts. The noise figure is typically 4.80B in a 75Q system and 6dB in a 50Q system. Until now, most RF or high-frequency designers had to settle for discrete or hybrid solutions to their amplification problems. Most of these solutions required trade-offs that the designer had to accept in order to fuse high-frequency gain stages. These include high-power consumption, large component count, transformers, large packages with heat sinks, and high part cost. The 5205 solves these problems by incorporating a wideband amplifier on a single monolithic chip. The part is well matched to 50Q or 75Q input and output impedances. The Standing Wave Rations in 50Q and 752 systems do not exceed 1.5 on either the input or output over the entire DC to 400MHz operating range. ORDERING INFORMATION PACKAGE DESCRIPTION ORDER CODE DESIGNATOR* 8-Pin Ceramic DIP 5205/BPA GDIP1-T8 *MIL-STD 1835 or Appendix A of 1995 Military Data Handbook ABSOLUTE MAXIMUM RATINGS SYMBOL Veo Supply voltage vi AC input voltage T March 11, 1992 PARAMETER 428 Product specification 5205 No external components are needed other than AC coupling capacitors because the 5205 is internally compensated and matched to 509 and 75Q. The amplifier has very good distortion specifications, with second and third-order intermodulation intercepts of +24dBm and +17dBm respectively at 100MHz (typical values). The part is matched well for 50Q test equipment such as signal generators, oscilloscopes, frequency counters and all kinds of signal analyzers. Other applications at 500 include mobile radio and data/video transmission in fiber optics, as well as broadband LANs and telecom systems. A gain greater than 20dB can be achieved by cascading additional 5205s in series as required, without any degradation in amplifier stability. PIN CONFIGURATION Vee D1] f@] Yoo vin [2] [7] Your GND [3] te GND GNo [4 }. [5] GND RATING 9 5 -65 to +150 853-0815 05969Philips Semiconductors Military Linear Products Product specification Wideband high frequency amplifier 5205 EQUIVALENT SCHEMATIC Yoc At 3 R2 as} WW Vout |__ as Ke $m Vin. o-_-___"14 Qa a4 $ RE2 RFI RE1 L 0s = RF2 March 11, 1992 429Philips Semiconductors Military Linear Products Wideband high frequency amplifier Product specification 5205 SUPPLY CURRENTmA 5 5.5 6 6.5 7 75 8 SUPPLY VOLTAGEV Figure 1. Supply Current vs Supply Voltage Zo = 500 Veo = av Ta=25'C Veo =7 Voc = 6v Veco = 5v NOISE FIGUREdBm rot 2 4 6 Byg2 2 4 6 8B 493 FREQUENCYMHz Figure 2. Noise Figure vs Frequency 25 jot 2 4 6 B42 2 4 6 8B 493 FREQUENCYMHz Figure 5. Saturated Output Power vs Frequency oa 2 20 I 1 5 3 G g 3 z = g & Et ui Ta =125C wn z wn z 10 10 101 2 4 6 8 492 2 4 6 B 493 101 2 4 6 B 492 2 4 6 B43 FREQUENCYMHz FREQUENCYMHz Figure 3. Insertion Gain vs Frequency (S21) Figure 4. Insertion Gain vs Frequency (S21) " 10 10 9 8 Veco = 8V a 7 7 6L Vcc = 6V E 6 E e cc= o ti i doa uw 3 a3 Voc =5V 7 Yoc=7 ay 2 a4 a 1 5 0 5 4 a -1 32 3 3 Zo = 501 4 4 Ta=25C 5 5 +4 +6 sol 2 4 6 By2 2 4 6 B 493 FREQUENCYMHz Figure 6. 1dB Gain Compression vs Frequency SECOND-ORDER INTERCEPTdBM 4 5 6 7 8 9 10 POWER SUPPLY VOLTAGEV Figure 7. Second-Order Output intercept vs Supply Voltage 30 E ; 25 & Ww 2 w 20 E ti 15 Zo = 502 5 Ta =25 g 10 F 5 4 5 6 7 8 9 40 POWER SUPPLY VOLTAGEV Figure 8. Third-Order Intercept vs Supply Voltage March 11, 1992 430Philips Semiconductors Military Linear Products Wideband high frequency amplifier Product specification 5205 20 2.0 19 1.9 18 18 17 17 ce a 16 z 16 5 7 45 2 15 5 t E a 4.4 2 z = 13 1.3 12 1.2 1 Ww 1.0 1.0 101 2 4 6 8102 2 4 68 8103 10! 2 4 6 810? 2 4 6 8103 FREQUENCY-MHz FREQUENCYMHz Figure 9. Input VSWR vs Frequency Figure 10. Output VSWR vs Frequency 10 a o J i -15 oO a a g 3 J z Voc = 6v 2 & Oo .. cc & 5 5 20 29 = 5022 y, bw Ta =25C wa 9 A 1 52 285 a 23 __-|+ +4 -30 tot 2 4 6 By2 2 4 6 8B 493 10! 2 4 5 8 w2 2 4 6 843 FREQUENCYMHz Figure 11, Input (S11) and Output (S29) Return Loss vs Frequency FREQUENCYMHz Figure 12. Isolation vs Frequency ($12) 8 ISOLATION GAIN-dB a 10 wt 2 4 6 Biy2 = 2 4 FREQUENCY-MHz 6 8 403 Figure 13. Insertion Gain vs Frequency (S21) INSERTION GAINdB Ta=125C Zg = 752 Vec = 6V tot 2 4 6 By2 2 4 FREQUENCYMHz 6 8 493 Figure 14. Insertion Gain vs Frequency (S21) March 11, 1992 431Philips Semiconductors Military Linear Products Wideband high frequency amplifier Product specification 5205 ELECTRICAL CHARACTERISTICS Vee = 6V, Zs = Z, = Zg = 50M, unless otherwise specified. SYMBOL PARAMETER TEST CONDITIONS Tamb = +25 C Tamb = 55 C, +125 UNIT MIN TYP MAX MIN TYP MAX loc Supply current Voc = 6.0V 20 24 32 19 33 mA Sat Insertion gain f = 100MHz 17 19 21 16.5 21.5 dB 811 Input return loss': 2 1 to 400MHz 12 29 dB Si Input return loss" 1 to 300MHz 9 dB S20 Output return loss". 2 1 to 400MHz 12 27 dB S20 Output return loss! 1 to 300MHz 9 dB Sis Isolation: 2 1 to 400MHz -18 -25 dB Si2 Isolation! 1 to 300MHz -18 dB Bw Bandwidth +0.5dB 300 MHz Bw Bandwidth -3dB 400 550 300 MHz En Noise figure f= 100MHz 48 dB En Noise figure f = 100MHz 6.0 dB Psat Saturated output power f = 100MHz +7.0 dBm Psat 1dB gain compression f = 100MHz +4.0 dBm IM Nowoptlostput) nn f = 100MHz +24 dBm Mg imorcopt toute) te f = 100MHz +17 dBm NOTES: 1. This parameter/test condition is guaranteed but not tested. 2. Typical value is for 1O0MHz operation. THEORY OF OPERATION The design is based on the use of multiple feedback loops to provide wideband gain Vv 2 v, (1) which is series-shunt feedback. There is also shunt-series feedback due to Reg and Reo which aids in producing wideband terminal impedances without the need for low value input shunting resistors that would degrade NF = ; th + Rea AG 10log : | Ro J where Ic; = 5.5mA, Re, = 122, rg = 1309, KT/q = 26mV at 25C and Ro = 50 for a 502 system and 75 for a 75Q system. = (Rey + Re,)/Rey dB The DC input voltage level V, can be determined by the equation: Vy = Veer + (Ic1 + 1C3)ReEy (3) where Req = 12Q, Vee = 0.8V, leq = 5MA and log = 7MA (currents rated at Voc = 6V). Under the above conditions, V; is approximately equal to 1V. Level shifting is achieved by emitter-follower Q3 and diode Q, which provide shunt March 11, 1992 together with good noise figure and terminal! impedance matches. Referring to the circuit the noise figure. For optimum noise performance, Re; and the base resistance of Q, are kept as low as possible while Rea is maximized. feedback to the emitter of Q, via Re;. The use of an emitter-follower buffer in this feedback loop essentially eliminates problems of shunt feedback loading on the output. the value of Re, = 140Q is chosen to give the desired nominal gain. The DC output voltage Vo can be determined by: Vo = Veo - (Ica + leg) Re (4) where Voc = 6V, Ro = 225Q, Ico = 7MA and leg = SMA. From here it can be seen that the output voltage is approximately 3.1V to give relatively equal positive and negative output 432 schematic in Figure 15, the gain is set primarily by the equation: The noise figure is given by the following equation: swings. Diode Qs is included for bias purposes to allow direct coupling of Rr2 to the base of Q,. The dual feedback loops stabilize the DC operating point of the amplifier. The output stage is a Darlington pair (Qg and Qs) which increases the DC bias voltage on the input stage (Q,) to a more desirable value, and also increases the teedback loop gain. Resistor Ro optimizes the output VSWR (Voltage Standing Wave Ratio). Inductors L, and L2 are bandwire and lead inductances which are roughly 3nH. These improve the high frequency impedance matches at inputPhilips Semiconductors Military Linear Products Product specification Wideband high frequency amplifier 5205 and output by partially resonating with 0.5pF of pad and package capacitance. POWER DISSIPATION CONSIDERATIONS When using the part at elevated temperature, the engineer should consider the power dissipation capabilities of each package. With this in mind, the following equation can be used to estimate the die temperature: Ty = Tamb + (Pp x Oya) where Tamb = Ambient Temperature, T; = Die Temperature, Pp = Power Dissipation = Icc x Voc, Oya = Package Thermal Resistance. At the nominal supply voltage of 6V. the typical supply current is 25mA (33MA Max). For operation at supply voltages other than 6V, see Figure 1 for Ice versus Voc curves. The supply current is inversely proportional to temperature and varies no more than 1mA between 25'C and either temperature extreme. The change is 0.1% per C over the range. The recommended operating temperature ranges are air-mount specifications. Figure 15. Schematic Diagram Vec RF CHOKE LL. DECOUPLING T CAPACITOR vin o[- [2 vout AC COUPLING COUPLING CAPACITOR CAPACITOR Figure 16. Circuit Schematic for Coupling and Power Supply Decoupling PC BOARD MOUNTING In order to realize satisfactory mounting of the 5205 to a PC board, certain techniques need to be utilized. The board must be double-sided with copper and all pins must be soldered to their respective areas (i.e., all GND and Vcc pins). The power supply should be decoupled with a capacitor as close to the Vcc pins as possible and an RF choke should be inserted between the supply and the device. Caution should be exercised in the connection of input and output pins. Standard microstrip should be observed March 11, 1992 wherever possible. There should be no solder bumps or burrs or any obstructions in the signal path to cause launching problems. The path should be as straight as possible and lead lengths as short as possible from the part to the cable connection. Another important consideration is that the input and output should be AC coupled. This is because at Voc = BV, the input is approximately at 1V while the output is at 3.1V. The output must be decoupled into a low impedance system or the DC Bias on the 433 output of the amplifier will be loaded down causing loss of output power. This circuit is shown in Figure 16. Follow these recommendations to get the best frequency response and noise immunity. The board design is as important as the integrated circuit design itself. The most important parameter is So. It is defined as the square root of the power gain, and, in decibels, is equal to voltage gain as shown below:Philips Semiconductors Military Linear Products Product specification Wideband high frequency amplifier 5205 Zp = 2, = Zo for the 5205 2 2 pe M 5205}-O 5 Vo 20 o4 2 1o 2p Vo Po _ 2p Vo? Oo ~ 0 __O'_p, P vi? vie 2p P, = V2 P, = Insertion Power Gain V, = Insertion Voltage Gain Measured value for the 5205 = | So, | 2 = 100 Po Pi= p=! Sar! ? = 100 V, = and V = = V/ Pj}=So1 = 10 | In decibels: Pag) = 10 Log | Soy | 2 = 2008 Vita) = 20 Log Sa; = 20dB Pigg) = Viiae) = S21iap) = 2008 INPUT RETURN LOSS = $1 dB Si; dB = 20 Log | Sy, | OUTPUT RETURN LOSS = S22 dB Soo dB = 20 Log l S22 | put vswa =! 1+S1! cys 141-Si, | b1+Si I OUTPUT VSWR = 15 11-Sy, | 1DB GAIN COMPRESSION AND SATURATED OUTPUT POWER The 1dB gain compression is a measurement of the output power level where the small-signal insertion gain magnitude decreases 1dB from its low power value. The decrease is due to nonlinearities in the amplifier, and indication of the point of transition between small-signal operation and the large signal mode. The saturated output power is a measure of the amplifiers ability to deliver power into an external load. It is the value of the amplifier's output power when the input is heavily overdriven. This includes the sum of the power in all harmonics. INTERMODULATION INTERCEPT TESTS The intermodulation intercept is an expression of the low level linearity of the amplifier. The intermodulation ratio is the March 11, 1992 Also measured on the same system are the respective voltage standing wave ratios. These are shown in Figure 18. The VSWR can be seen to be below 1.5 across the entire operational frequency range. difference in dB between the fundamental output signal level and the generated distortion product level. The relationship ratio is illustrated in Figure 19, which shows product output levels plotted versus the level of the fundamental output for two equal strength output signals at different fraquencies. The upper line shows the fundamental output plotted against itself with a 1dB to 1dB slope. The second and third order products lie below the fundamentals and exhibit a 2:1 and 3:1 slope respectively. The intercept point for either product is the intersection of the extensions of the product curve with the fundamental output. The intercept point is determined by measuring the intermodulation ratio at a single output level and projecting along the appropriate product slope to the point of intersection with the fundamental. When the intercept point is known, the intermodulation ratio can be determined by the reverse process. The second order IMR is equal to the difference between the second order 434 Relationships exist between the input and output return losses and the voltage standing wave ratios. these relationships are as follows: intercept and the fundamental output level. The third order IMR is equal to twice the difference between the third order intercept and the fundamental output level. These are expressed as: IP2 = Po + IMR2 IP3 = Po + IMRy/2 where Po is the power level in dBm of each of a pair of equat level fundamental output signals, IP2 and IPg are the second and third order intermodulation ratios in dB. The intermodulation intercept is an indicator of intermodulation performance only in the smail signal operation range of the amplifier. Above some output level which is below the 1dB compression point, the active device moves into large signal operation. At this point the intermodulation products no longer follow the straight line output slopes, and the intercept description is no longer valid. It is therefore important to measure IP2 and !P3 at output levels well below 1dB compression. One must be careful, however, not to select tooPhilips Semiconductors Military Linear Products Product specification Wideband high frequency amplifier 5205 low levels because the test equipment may not be able to recover the signal from the noise. For the 5205 we have chosen an output level of -10.5dBm with fundamental frequencies of 100.000 and 100.01MHz, respectively. S21 $12 Figure 17. Two-Port Network Defined ADDITIONAL READING ON SCATTERING PARAMETERS For more information regarding S-parameters, please refer to: High-Frequency Amplifiers by Ralph S. Carson of the University of Missouri, Rolla, Copyright 1985; published by John Wiley & Sons, Inc. ~ S-Parameter Techniques for Faster, More Accurate Network Design, H.P. App Note 95-1, Richard W. Anderson, 1967, HP Journal. S-Parameter Design, H.P. App Note 154, 1972. 10! 2 4 6 8102 2 4 6 8103 104 4 6 8102 2 4 6 8103 FREQUENCY MHz FREQUENCY - MHz a. Input VSWR vs Frequency b. Output VSWR vs Frequency Figure 18. March 11, 1992 435Philips Semiconductors Military Linear Products Product specification Wideband high frequency amplifier 5205 | [| THIRD ORDER <! 2ND ORDER +20 |_ INTERCEPT POINT ~| [_ INTERCEPT | ! i POINT 1dB COMPRESSION POINT ~. +10 | Zz FUNDAMENTAL ~ RESPONSE LY - _Y 10 / : /. [ - 2ND ORDER -20 | __. L / / ___ RESPONSE | | / / [. 3RD ORDER 30 [__ / RESPONSE -40 / od -60 ~50 Be SN J 0 20 -10 o +10 +20 +30 +40 INPUT LEVEL d8m Figure 19. Output dBm vs Input dBm March 11, 1992 436