TDD switch, driving and the integrated receiving front-end of LNA and preparation method thereof
Technical field
What the present invention relates to is a kind of TDD switch, driving and the integrated receiving front-end of LNA and preparation method thereof, belongs to mobile communication technology field.
Background technology
The TD-SCDMA of 3G (Third Generation) Moblie and new generation broadband mobile communication and WIMAX system and TD-LTE system all adopt tdd mode, in base station system, transmission channel power amplifier (PA) is controlled Transmit enable between antenna (ANT) by a high power switch (SW) to antenna (ANT) and receive path; The small-signal that the low noise amplifier amplifying antenna of receive path is received from air interface, its noise, non-linear, the performances such as coupling are most important to whole receiver.
Present mobile communication technology requires radio-frequency devices, module to high selectivity, the future development of low cost and miniaturization.The development of the third generation the 4th Generation Mobile Communication System, traffic rate improves greatly, and radio-frequency devices, module are had higher requirement in high-power and high integration.
Summary of the invention
What the present invention proposed is a kind of TDD switch, driving and the integrated receiving front-end of LNA and preparation method thereof, its object is intended to 1) meet the condition of work of the very big power switching controls of TDD system base-station power amplifier, the safe and reliable work of energy, and guarantee that the receive path of complete machine has the receiving sensitivity of extremely low noise factor and Geng Gao; 2) improve the integrated level of receiving front-end, in QFN6 * 6-40L standard packaging, integrated power switch, driving and LNA chip, reduce costs Optimal performance.
Technical solution of the present invention: a kind of TDD switch, driving and the integrated receiving front-end of LNA, its structure is that transmission channel adopts a PIN diode, and receiving branch adopts two PIN diode and a chip capacity to form tandem tap circuit as switch element; After receiving branch, two GaAs LNA chips of cascade, form whole receive path; A GaAs switch chip is for bypass second level LNA.It is characterized in that: in QFN6 * 6-40L standard packaging, make collection switch, driving and the integrated receiving front-end of LNA, aluminium nitride substrate, GaAs LNA chip, silicon drive chip and GaAs switch chip to be bonded in respectively on QFN6 * 6-40L standard packaging lead frame central metal substrate; On aluminium nitride substrate, bonding three PIN diode chips, a chip capacity form transmit-receive switch commutation circuit respectively, and the driving of switch switching circuit drives chip to realize by integrated silicon.
PIN diode chip, chip capacity, GaAs LNA chip, silicon drive between chip and GaAs switch chip and connect with gold wire bonding, and PIN diode chip, chip capacity, GaAs LNA chip, silicon drive between chip and GaAs switch chip and the corresponding pin of QFN6 * 6-40L standard packaging lead frame and connects with gold wire bonding.
The preparation method of switch, driving and the integrated receiving front-end of LNA, comprises the following steps:
1) on QFN6 * 6-40L standard packaging lead frame central metal substrate, with the bonding aluminium nitride AlN substrate of silver slurry, GaAs LNA chip, GaAs switch chip and silicon, drive chip;
2) on aluminium nitride AlN substrate with three PIN diode chips and the electric capacity chip of the bonding power switch of silver slurry;
3) between PIN diode chip, electric capacity chip and aluminium nitride substrate, between PIN diode chip and QFN6 * 6-40L standard packaging lead frame pin, aluminium nitride substrate and QFN6 * 6-40L standard packaging lead frame pin, GaAs LNA chip, GaAs switch chip and silicon drive between chip and QFN6 * 6-40L standard packaging lead frame pin and all by bonding gold wire, are connected.
The present invention compared with prior art, has following good effect:
1) can in QFN6 * 6-40L standard packaging, realize switch, driving and low noise integrated, and can safe and reliable work under the high-power condition of radio frequency continuous wave 120W.
2) met the requirement of TD-SCDMA, WIMAX and the high-power switching controls of TD-LTE system base-station power amplifier; Meet low-noise factor and the gain requirement of TD-SCDMA, WIMAX and TD-LTE frequency range receive path, whole receiving front-end noise factor can be low to moderate 0.7dB, and gain representative value reaches 33 dB, has higher sensitivity and integrated level, and cost is low, and performance is excellent.
3) in receive path, adopt two-stage GaAs LNA chip, there is second level LNA bypass functionality, can carry out gain-adjusted according to the size of input signal, under the larger application scenarios of input signal, by gain-adjusted, increase the dynamic range of subsequent conditioning circuit.Electricity under the LNA of the second level in the time of bypass, the power consumption while reducing bypass condition.During transmission channel conducting, the two poles of the earth LNA can, with electric at present, reduce the power consumption of whole radio-frequency front-end.
4) in QFN6 * 6-40L standard packaging, to realize switch, driving and LNA integrated in the present invention, more existing receiving front-end module, and size is less, and product versatility is good, has better large-scale production, effectively reduces the cost of product itself; Integrated level is higher, effectively reduces the size of user's peripheral circuit, reduces circuit cost.
5) the present invention is ultra broadband receiving front-end, and match circuit all completes in periphery, can be applied to by different match circuits hundreds of million to the various communication systems of several gigabits, has good application flexibility.
6) adopt multi-chip assembling (MCM) technology, the direct bond processing method of bare chip, thereby reduced the thermal resistance between chip and substrate, and avoided the impact on performance of additive effect that encapsulation brings, high power switch adopts high heat conduction aluminium nitride (ALN) substrate to carry out circuit design, by high heat conduction silver slurry, be bonded on QFN6 * 6-40L standard packaging central metal substrate, reduced the thermal resistance between PIN diode chip and application circuit.The module electrical property that adopted this design optimization, makes the reliability of module, and product electrical property all gets a promotion, and has reduced the use cost of module simultaneously.
The receiving front-end of collection switch, driving and the LNA one that the present invention be directed to the machine system of the TDD communication standards such as TD-LTE and research and develop.Adopt advanced multichip modules technology (MCM), standard packaging technology, product has less loss, more high-isolation, more high power capacity, higher reliability, less noise factor, higher gain in the TDD of 3G and 4G mode of operation system.
Accompanying drawing explanation
Fig. 1 is circuit structure of the present invention and die bonding, Bonding schematic diagram, 1 to 40 40 pins of totally 40 numeral QFN6 * 6-40L-40L standard packaging in figure.
Fig. 2 is aluminium nitride substrate schematic diagram.
Fig. 3 is LNA chip schematic diagram.
Fig. 4 is switch chip schematic diagram.
Fig. 5 is that integrated silicon drives chip schematic diagram.
Fig. 6 is application schematic diagram of the present invention.
Fig. 7 is the circuit diagram of Fig. 6.
In figure 1 is power amplifier, the 2nd, the integrated receiving front-end of TDD switch, driving and LNA, the 3rd, and antenna, the 4th, reception & disposal unit, the 5th, controls and match circuit.
Embodiment
The integrated receiving front-end of TDD switch, driving and LNA, its structure is that transmission channel adopts a PIN diode, receiving branch adopts two PIN diode and a chip capacity to form tandem tap circuit as switch element; After receiving branch, two GaAs LNA chips of cascade, form whole receive path; A GaAs switch chip is for bypass second level LNA; In QFN6 * 6-40L standard packaging, make collection switch, driving and the integrated receiving front-end of LNA, aluminium nitride substrate, GaAs LNA chip, silicon drive chip and GaAs switch chip to be bonded in respectively on QFN6 * 6-40L standard packaging lead frame central metal substrate; On aluminium nitride substrate, bonding three PIN diode chips, a chip capacity form transmit-receive switch commutation circuit respectively, and the driving of switch switching circuit drives chip to realize by integrated silicon.
PIN diode chip, chip capacity, GaAs LNA chip, silicon drive between chip and GaAs switch chip and connect with gold wire bonding, and PIN diode chip, chip capacity, GaAs LNA chip, silicon drive between chip and GaAs switch chip and the corresponding pin of QFN6 * 6-40L standard packaging lead frame and connects with gold wire bonding.
The preparation method of switch, driving and the integrated receiving front-end of LNA, comprises the following steps:
1) on QFN6 * 6-40L standard packaging lead frame central metal substrate, with the bonding aluminium nitride AlN substrate of silver slurry, GaAs LNA chip, GaAs switch chip and silicon, drive chip;
2) on aluminium nitride AlN substrate with three PIN diode chips and the electric capacity chip of the bonding power switch of silver slurry;
3) between PIN diode chip, chip capacity and aluminium nitride AlN substrate, between PIN diode chip and QFN6 * 6-40L standard packaging lead frame pin, aluminium nitride AlN substrate and QFN6 * 6-40L standard packaging lead frame pin, GaAs LNA chip, GaAs switch chip and silicon drive between chip and QFN6 * 6-40L standard packaging lead frame pin and all by bonding gold wire, are connected.
Described QFN6 * 6-40L standard packaging lead frame of selecting central metal substrate with the bonding aluminium nitride AlN substrate of high heat conduction silver slurry, improves the heat-sinking capability of circuit on QFN6 * 6-40L standard packaging lead frame central metal substrate, reduces thermal resistance.
Described on AlN substrate with PIN diode chip and the chip capacity of the bonding high power switch of high heat conduction silver slurry, between PIN diode chip and aluminium nitride AlN substrate, by gold wire bonding, be connected, between chip capacity and aluminium nitride AlN substrate, by gold wire bonding, be connected.
Described on QFN6 * 6-40L standard packaging lead frame central metal substrate, with the bonding integrated gallium arsenide LNA chip of silver slurry, GaAs switch chip and silicon, drive chip, integrated gallium arsenide LNA chip, GaAs switch chip and silicon drive between chip and QFN6 * 6-40L standard packaging lead frame correspondence position and are connected by gold wire bonding.
Below in conjunction with accompanying drawing, technical scheme of the present invention is described in further detail:
As shown in Figure 1, the structure of switch, driving and the integrated receiving front-end of LNA, adopt high heat conduction silver slurry aluminium nitride AlN substrate A, GaAs LNA chip E, GaAs switch chip F and silicon drive chip G to be bonded on the central metal substrate in QFN6 * 6-40L-40L standard packaging lead frame.
Then, adopt high heat conduction silver slurry that high-power PIN diode chip B and middle power diode chip C and chip capacity D are bonded on aluminium nitride AlN substrate.
Diode chip for backlight unit, chip capacity, GaAs LNA chip, GaAs switch chip, silicon are driven between chip and said chip and the corresponding pin of QFN6 * 6-40L-40L standard packaging lead frame between with gold wire bonding, connect.
After above-mentioned technique completes, by device package, test.
Embodiment
Substrate is selected the aluminium nitride AlN that 0.2mm is thick, according to the circuit diagram of Fig. 2, carries out pcb board electric circuit diagram design, surface gold-plating.High-power PIN diode chip B mainly considers from the following aspect: the reverse withstand voltage 300V that is greater than, junction capacitance is less than 0.2P, series resistance is less than 0.5 ohm, thermal resistance be less than 15 degree/watt.According to these, require to select PIN diode chip.Two other PIN diode chip C is mainly from the reverse withstand voltage 200V that is greater than, and junction capacitance is less than 0.05P, and series resistance is less than 0.5 ohm.According to these, require to select PIN diode chip.Electric capacity D single-layer ceramic chip capacity.
The effect of GaAs the low noise amplifier chip is to amplify to received signal, forms receive path, meets noise factor and the gain requirement of receive path.Second level LNA can bypass by GaAs switch chip, meets the demand that in practical application, subsequent conditioning circuit dynamic range is adjusted.In the time of bypass, electricity under the LNA of the second level, reduces power consumption.
As shown in Figure 4: during emission state, power amplifier 1 work, power is exported by power amplifier, through TDD switch, driving and the integrated receiving front-end 2 of LNA, is switched to antenna 3; During accepting state, signal is inputted by antenna 3, through TDD switch, driving and the integrated receiving front-end 2 of LNA, is switched to reception & disposal unit 4.Passage switching controls and coupling are realized by control and match circuit 5.
Under normal temperature, the integrated receiving front-end of TDD switch, driving and LNA has in the leading indicator of TD-LTE:
1. receive path: noise factor representative value is 1.1 dB, and gain representative value is 33dB, input 1dB compression point is-15dBm.
2. transmission channel: power capacity is 120W, and insertion loss representative value is 0.3dB.