## 1 Introduction  
Active electronically scanned arrays (AESA) with a number of transmit/receive (T/R) modules are widely adopted due to the rapid change of beam shape and beam direction [1; 2; 3]. Phase shifters are used to adjust the phase of each element and yet beam squint still occurs for wide-band applications [4; 5; 6; 7]. Therefore, true-time-delay (TTD) modules are essential in phased array systems such as AESA radars to meet the increasing demand of broader bandwidth and wider scanning angle [8; 9; 10; 11]. [PERSON] et al., reported a 300-450 MHz dipole linear array antenna and TTDs can be implemented by using appropriate lengths of coaxial cable transmission lines in order to maintain the main beam pointed at a fixed 40-degree angle from broadside over the operating bandwidth [12]. However, more and more functions are designed to be combined with TTD function to meet the increasing demand of higher integration density and smaller module size. [PERSON] et al., reported an X-band receiver integrated with a subarray-level 5-bit TTD module [13]. [PERSON] et al., reported a Ka-band high integration receiver module which combines TTD units at sub-array level and phase shifters at array-element level to realize a 1.6 GHz instantaneous bandwidth [14]. [PERSON] et al. reported an X-band 5-bit time-delay amplifier module in which a time-delay function is realized by coplanar waveguide (CPW) transmission lines [15]. [PERSON] et al. reported a 6-bit TTD amplifier module for X-band subarray phased arrays where CPW transmission lines are also used as time delay units [16]. [PERSON] et al., reported a C-band subarray drive time-delay module which integrates 5-bit time-delay, amplification and power dividing/combining [17; 18]. [PERSON] et al., reported an X-band subarray drive time-delay module which integrates 5-bit time-delay, and receives and transmits gain compensation [19]. In both modules, microstrip lines and striplines with different lengths are used to realize time-delay function. However, using CPW transmission lines or microstrip lines and striplines as delay paths results in an unacceptable amount of module area for the required time delay, and the insertion loss of different time delay states varies substantially [20; 21]. In terms of electrical design and micro/macro-packaging fabrication, electronic delay lines using monolithic microwave integrated circuit (MMIC) devices can be more easily implemented through multi-chip module (MCM) technology for higher integration and smaller circuit diagrams [22; 23; 24; 25]. [PERSON] et al., reported a C-band multi-channel 9-bit TTD amplification module, and GaAs MMICs are adopted to realize TTD function by switching between a reference path and a delay path [26; 27]. However, on the one hand, extra bi-directional amplifiers are needed to compensate the signal transmission loss induced by insertion loss of TTD MMICs [28]. Not only TTD units but also amplifiers are integrated in one active MMIC device to combat insertion losses and to provide gain [29; 30]. On the other hand, it is barely reported that TTD modules and T/R modules are integrated as a whole. Integrating a TTD module with a T/R module can greatly improve the packaging density and simplify the interconnection among modules inside a complicated antenna system. In this paper, a LTCC-based Ku-band TTD module is integrated with a Ku-band T/R module inside the same shell. LTCC technology is very suitable for the manufacturing of mixed-signal multi-layer substrates, which can realize the combined design of microwave circuits, logic control circuits and power management circuits on different layers. The TTD module integrates a 7-bit time-delay, receive gain compensation and transmit power drive, which are realized through active MMICs. The paper is organized as follows: the topography and link budget of the 8-channel T/R module with 7-bit TTD are presented in Section 2. Section 3 reports the simulation results of the SMP-microstrip vertical transition and strip line power divider for the Ku-band.