X3DC18E2S

X3DC18E2S Rev F Doherty Combiner Description: The X3DC18E2S is a low profile, high performance Doherty Combiner in a new easy to use, manufacturing friendly surface mount package. The X3DC18E2S is designed particularly for Doherty Amplifier applications, where tightly controlled phase and amplitude imbalance as well as low insertion loss are required for maximum and low power condition. It can be used in high power applications up to 200 watts. Parts have been subjected to rigorous qualification testing and they are manufactured using materials with coefficients of thermal expansion (CTE) compatible with common substrates such as FR4, G-10, RF-35, RO4350 and polyimide. Produced with 6 of 6 RoHS compliant tin immersion finish. Features: • • • • • • • Electrical Specifications ** 1805 - 1880 MHz High Power Low Amp Imbalance Very Low Loss Production Friendly Tape and Reel Lead Free Frequency Return Loss [1] Insertion Loss [1] Amplitude Imbalance [1] Phase Imbalance [1] MHz dB Min dB Max dB Max Degrees 1805 – 1880 20 0.15 ±0.12 90 ± 3.0 Operating Temp. Return Loss [2] Insertion Loss [2] Port Extension[3] Power[4] ºC dB Min dB Max Degrees Avg. CW Watts @95 ºC -55 to +150 20 0.20 3 200 **Specification based on performance of unit properly installed on TTM Test Board [1] At maximum power condition, Doherty combiner functions as an equal-split power combiner. [2] At low power condition, Doherty combiner functions as a 100Ω to 50Ω impedance transformer. [3] There are short 50 ohm lines associated with input ports of 3° at 1842MHz. Details in page 2. Mechanical Outline 1 X3DC18E2S Rev F Doherty Amplifier Configuration Doherty Combiner Pin Configuration The X3DC18E2S has an orientation marker to denote Pin 1. Once port one has been identified the other ports are known automatically. Please see the chart below for clarification: Pin 1 Combining Port Pin 2 Not Used Pin 3 Peak Amp Port Pin 4 Main Amp Port There are inevitably short lines associating with input ports in some high frequency band parts. The length of the short line is specified as electrical length at center frequency and noted as port extension in this datasheet. The designer should take this length into the consideration to optimize the offset line length. 2 X3DC18E2S Rev F Insertion Loss and Power Derating Curves Insertion Loss Derating Power Derating The insertion loss, at a given frequency, of a group of doherty combiners is measured at 25°C and then averaged. The measurements are performed under small signal conditions (i.e. using a Vector Network Analyzer). The process is repeated at 95°C and 150°C. A best-fit line for the measured data is computed and then plotted from -55°C to 150°C. The power handling and corresponding power derating plots are a function of the thermal resistance, mounting surface temperature (base plate temperature), maximum continuous operating temperature of the Doherty combiner, and the thermal insertion loss. The thermal insertion loss is defined in the Power Handling section of the data sheet. As the mounting interface temperature approaches the maximum continuous operating temperature, the power handling decreases to zero. If mounting temperature is greater than 105°C, Xinger doherty combiner will perform reliably as long as the input power is derated to the curve above. 3 X3DC18E2S Rev F Typical Performance (-55°C, 25°C, 95°C ): 1805 – 1880MHz Return Loss for X3DC18E2S (Maximum Power Condition) 0 -55ºC 25ºC 95ºC Return Loss (dB) -10 -20 -30 -40 -50 1810 1820 1830 1840 1850 Frequency (MHz) 1860 1870 1880 Insertion Loss for X3DC18E2S (Maximum Power Condition) 0 -55ºC 25ºC 95ºC -0.02 -0.06 -0.08 -0.1 -0.12 -0.14 1810 1820 1830 1840 1850 Frequency (MHz) 1860 1870 1880 Phase Balance for X3DC18E2S Amplitude Balance for X3DC18E2S 0.2 -55ºC 25ºC 95ºC -86 -55ºC 25ºC 95ºC 0.15 0.1 Amplitude Balance (deg) -88 Phase Balance (deg) Insertion Loss (dB) -0.04 -90 -92 0.05 0 -0.05 -0.1 -0.15 -94 1810 1820 1830 1850 1840 Frequency (MHz) 1860 1870 1880 -0.2 1810 1820 1830 1840 1850 Frequency (MHz) 1860 1870 1880 4 X3DC18E2S Rev F Definition of the Specifications To guarantee the part performance in Doherty architecture, the part is specified in Doherty operation for maximum power condition and low power condition. The following specification definition assumes the extra port extension is already applied to the raw S parameter and the parts is measured with Pin n connected to Port n (where n=1, 2, 3, 4). Maximum power condition Under the maximum power condition, the symmetrical Doherty architecture requires main amplifier and peak amplifier to work at full capacity with the optimum termination (50 Ω). The two amplifiers should deliver RF power of equal magnitude and 90 degree phase difference. Doherty combiner functions as a coherent power combiner and supplies the 90 degree phase compensation. The following specification is defined with 50 Ω port impedance at three ports for this condition. The return loss and the insertion loss in max power mode are not affected by the 50 ohm lossless port rotation mentioned in electrical spec table in page 1. The phase imbalance and the amplitude imbalance are not affected either since port rotation are taken off equally from the main and the peak amp port. Parameter Return Loss Insertion Loss Phase Imbalance Amplitude Imbalance Definition The impedance match at the combining port to a 50Ω system. The combined power divided by the sum of input power under the perfect combining condition. The phase difference between Peak-Combined path and MainCombined path at ωc = 1842MHz The magnitude difference between Peak-Combined path and Main-Combined path. Low power condition Mathematical Representation 20log| S11 | 10log(|S13 |2 + |S14 |2 ) Phase (S14 (ωc )) − Phase (S13 (ωc )) 1 (20log| S14 | − 20log| S13 |) 2 Under low power condition, the Doherty operation turns off peak amplifier and requires main amplifier to be terminated with double of the optimum impedance (100 Ω). In this configuration, Doherty combiner servers as an impedance transformer transforming 50 Ω at combining port to 100 Ω at main amplifier port. The following specification is defined under the port impedance condition of Port 1 (Combining Port) 50 Ω, Port 4 (Main Amp Port) 100 Ω and Port 3 (Peak Amp Port) open. With the peak amp left off, the extra line length in that port (see figure in page 2) acts as an open stub which shifts the low power mode return loss null and insertion loss. The offset line length needs to be adjusted taking the port rotation number into consideration so that the junction of 50 Ω and 35 Ω transmission line sees high impedance instead of the part edge. The return loss and the insertion loss defined below are after the offset line adjustments specified in the spec table. Parameter Return Loss Insertion Loss Definition The impedance match of the 50 to100 Ω transformer. The output power divided by input power. Mathematical Representation 20log| S11 | 20log| S41 | 5 X3DC18E2S Rev F Packaging and Ordering Information: Parts are available in reel. Packaging follows EIA 481-2. Parts are oriented in tape and reel as shown below. Minimum order quantities are 2000 per reel. .079 [2.00] .012 [0.30] Ø.059 [Ø1.50] .157 [4.00] .069 [1.75] .453 [11.50] .591 [15.00] Ø.059 [Ø1.50] .228 [5.80] .315 [8.00] XX XX .094 [2.40] .945 [24.00] Contact us: rf&s_support@ttm.com 6