CN102386874A - Wideband reconfigurable load network - Google Patents

Abstract

The invention belongs to the technical field of radio frequency integrated circuits, in particular to a broadband reconfigurable load network applied in a broadband multi-mode receiver. It consists of an inductor, a voltage-controlled resistor array (DCRA), and a voltage-controlled capacitor array (DCCA). The voltage-controlled capacitor array and the inductor are connected in parallel to form an LC parallel resonant network, and the resonant network is connected in series with the voltage-controlled resistor array to form an RLC load network; the resonant frequency is adjusted by controlling the switch of the capacitor array by the voltage; by adjusting the switch of the resistor array by the voltage Gain in different frequency bands. The invention has a simple structure and realizes the reconfiguration of the load network impedance in different frequency bands.

Description

A Broadband Reconfigurable Load Network

technical field

The invention belongs to the technical field of radio frequency integrated circuits, and in particular relates to a broadband reconfigurable RLC load network.

The load network has the characteristics of simple structure, flexible reconfiguration, and can be digitally controlled for different applications, so that the load network can work at different frequencies. It is especially used in the load of low-noise amplifiers and mixers at the front end of multi-mode receivers at 1.8~10.6GHz. It is suitable for multi-mode receiver systems including GSM, LTE, WCDMA, Bluetooth, WLAN, UWB, etc.

Background technique

Multi-mode RF receiver systems are currently a research hotspot in academia and industry. The compatibility of multiple communication modes is realized through a single receiver link, which can reduce the power consumption of the whole machine and the area of the chip at the same time. In receiver front-end circuits, such as low-noise amplifiers and mixers, the load circuit can affect the frequency band, bandwidth, and gain of the front-end circuit. Therefore, how to design a load circuit that can flexibly work in different frequency bands is very important for multi-mode receivers.

Contents of the invention

The object of the present invention is to provide a broadband reconfigurable load network applied in a broadband multi-mode receiver, so that the circuit can work in the frequency bands required by different communication modes through voltage control switches.

The wideband reconfigurable load network in the wideband multimode receiver involved in the present invention can cover a wide frequency range of 1.8 to 10.6 GHz through the control of DCCA and DCRA, and the structure can be applied to low noise amplifier loads and mixers In the load circuit, it has the characteristics of small area, reconfigurable, and wide coverage.

The present invention provides a wideband reconfigurable load network, as shown in Figure 1, consisting of an inductor L, a voltage-controlled capacitor array DCCA and a voltage-controlled resistor array DCRA; the voltage-controlled capacitor array is connected in parallel with the inductor to form an LC A parallel resonant network, the resonant network is connected in series with the voltage-controlled resistor array in sequence to form an RLC load network; the resonant frequency is adjusted through the voltage-controlled switch of the capacitor array; and the gain under different frequency bands is adjusted through the switch of the voltage-controlled resistor array.

Further, as shown in FIG. 1, each column of the capacitor array in the voltage control capacitor array DCCA is composed of a capacitor Ca connected to a switch SWcap, and then connected to a capacitor Cb in sequence. Such capacitor arrays are connected in parallel in multiple stages to form the voltage control capacitor array.

Further, as shown in FIG. 1 , each column of the resistor array in the voltage-controlled resistor array DCRA is composed of a switch SWres connected to a resistor R, and such resistor arrays are connected in parallel in multiple stages to form the above-mentioned voltage-controlled resistor array.

Further, as shown in FIG. 2 , by turning off the switches to open different combinations, the reconfigurability of the resonance point of the load network is realized.

Further, in order to solve the problem of lower load impedance Z _load at low frequencies as shown in Figure 1, by changing the switch off and on combination of the control voltage control resistor array DCRA, the resistance value of the voltage control resistor array DCRA array is increased , increase the load impedance Z _load at low frequency; increase the load impedance Z _load at high frequency by reducing the equivalent resistance of the voltage control resistor array DCRA array. The realization effect is shown in Figure 3 and Figure 4.

Improvement of the present invention is mainly reflected in:

1. A new type of broadband reconfigurable load network is proposed, which can realize the load network to work in different frequency bands by changing the control voltage of DCCA and DCRA. The coverage range is from 1.8 to 10.6GHz, which can cover the existing main communication standards.

2. Study the characteristics of the RLC network, and adjust the Z _load under different standards by using the characteristics of different equivalent load network impedance values Z _load corresponding to different network parameter values at high and low frequencies;

3. The network only uses one inductor, which can cover the frequency band from 1.8 to 10.6 GHz, saving the area.

The load network of the present invention has the characteristics of simple structure, flexibility and reconfiguration, and can carry out digital control for different applications, so that the load network can work at different frequencies. It is especially used in the load of low-noise amplifiers and mixers at the front end of multi-mode receivers at 1.8~10.6GHz. It is suitable for multi-mode receiver systems including GSM, LTE, WCDMA, Bluetooth, WLAN, UWB, etc.

Description of drawings

Fig. 1: A block diagram of a design example of a broadband reconfigurable load network of the present invention.

Fig. 2: The effect of changing the equivalent capacitance value of DCCA on Z _load in the broadband reconfigurable load network of the present invention.

Figure 3: The wideband reconfigurable load network of the present invention changes DCRA to cooperate with DCCA to achieve gain improvement at low frequencies.

Figure 4: The wideband reconfigurable load network of the present invention changes DCRA to cooperate with DCCA to achieve gain improvement at high frequencies.

Detailed ways

Further describe the present invention below by embodiment in conjunction with accompanying drawing. the

As shown in Figure 1, by selecting the switching voltage, the load network can change the equivalent impedance value Z _load in the 1.8-10.6 GHz frequency band to meet the requirements of various communication standards and realize variable gain and variable bandwidth. reconfigurable.

Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention rather than limit it. Those of ordinary skill in the art should understand that the technical solution of the present invention can be modified or equivalently replaced without departing from the spirit of the technical solution of the present invention and scope, which should be included in the scope of the claims of the present invention.

Claims (3)

1. A broadband reconfigurable load network, characterized in that: It consists of an inductor, a voltage-controlled capacitor array and a voltage-controlled resistor array, the voltage-controlled capacitor array is connected in parallel with the inductor to form an LC parallel resonant network, and the resonant network is sequentially connected in series with the voltage-controlled resistor array to form an RLC load network; The resonant frequency is adjusted by controlling the switch of the capacitor array by the voltage; the gain of different frequency bands is adjusted by controlling the switch of the resistor array by the voltage. 2. The broadband reconfigurable load network as claimed in claim 1, wherein the voltage control capacitor array is composed of multiple columns of capacitor arrays connected in parallel, wherein each column of capacitor arrays is connected by capacitor Ca to switch SWcap, switch SW and then Connect capacitors Cb in sequence to form. 3 . The broadband reconfigurable load network according to claim 1 , wherein the voltage control resistor array is composed of multiple columns of resistor arrays connected in parallel, wherein each column of resistor arrays is composed of a switch SWres connected to a resistor R. 4 .

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